Three students measured the length of a stamp whose accepted length is 2.71 cm, on the basis of the table student 2 is both precise and accurate, therefore the correct answer is option B.
What is a unit of measurement?A unit of measurement is a specified magnitude of a quantity that is established and used as a standard for measuring other quantities of the same kind. It is determined by convention or regulation.
The degree to which a measurement is accurate in relation to its true value. The degree to which the same results are produced by repeated measurements under the same circumstances is known as precision.
Thus, according to the chart, student 2 is both exact and accurate, hence the proper response is option B. Three students measured the length of a stamp, and the approved length is 2.71 cm.
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What keeps the sun shining
Answer:
The Sun shines by turning hydrogen into helium in its core.
Explanation:
This process is called nuclear fusion. Fusion happens when lighter elements are forced together to become heavier elements. When this happens, a tremendous amount of energy is created.
Lila is a track and field athlete. She must complete four laps around a circular track. The track itself is a 400 meter track and it took her 6 minutes total to complete. Which best describes her speed and velocity? A. Her speed is 4.4 m/s, and her velocity is 0 m/s B. Her speed is 1.1 m/s, and her velocity is 0 m/s C.Her speed is 0 m/s, and her velocity is 2400 m/s D. Her speed is 4.4 m/s, and her velocity is 4.4 m/s
Answer:
Her speed is 1.1 m/s, and her velocity is 0 m/s
Explanation:
Speed = Distance covered/Time
Given
Distance = 400m
Time = 6minutes = 6*60 = 360 secs
Substitute the given parameter into the formula;
Speed = 400/360
Speed = 1.1m/s
Since the track is a circular track, the displacement will be zero. She is only moving in a circular path (no direction)
Velocity = Displacement/Time
Velocity = 0/3600
Velocity = 0m/s
Hence her speed is 1.1 m/s, and her velocity is 0 m/s
Answer: Her speed is 1.1 m/s, and her velocity is 0 m/s
Explanation:
true or false
Impulse is defined as the force exerted on an object times the time it lasts.
Answer: true
Explanation: when two objects collide and completely bounce apart with no lasting deformation or generation of heat, the collision is said to be elastic.
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A block attached to a horizontal spring of force constant 75N/m undergoes SHM with an amplitude of 0.15m. If the speed of the mass is 1.7 m/s when the displacement is 0.12m from the equilibrium position, what is the mass of the block?
Answer:
x = A sin w t for SHM where w = angular frequency
sin w t = x / A = .12 / .15 = .8 where w t is the angle in degrees
w t = 53.1 deg (w itself is in rad / sec)
since v = A w cos w t
then v / x = w cos w t / sin w t = w / tan w t
w = v / x * tan 53.1 = 1.7 / .12 * tan 53.1 = 18.9 /sec
Also for SHM w = (k / m)^1/2
m = k / w^2 = 75 / 18.9^2 = .21 kg
A rock is dropped from a garage roof from rest. The roof is 6m from the ground. Determine how long it takes the rock to hit the ground.
Answer:
The rock takes 1.22 seconds to hit the ground
Explanation:
Free Fall Motion
A free-falling object falls under the sole influence of gravity. Any object that is being acted upon only by the force of gravity is said to be in a state of free fall. Free-falling objects do not encounter air resistance.
If an object is dropped from rest in a free-falling motion, it falls with a constant acceleration called the acceleration of gravity, which value is g = 9.8 m/s^2.
The final velocity of a free-falling object after a time t is given by:
vf=g.t
The distance traveled by a dropped object is:
[tex]\displaystyle y=\frac{gt^2}{2}[/tex]
If we know the height h from which the object was dropped, we can find the time it takes fo hit the ground:
[tex]\displaystyle t=\sqrt{\frac{2y}{g}}[/tex]
[tex]\displaystyle t=\sqrt{\frac{2\cdot 6}{9.8}}[/tex]
[tex]t=1.22\ sec.[/tex]
The rock takes 1.22 seconds to hit the ground
The time taken for the rock to hit the ground from the roof top is 1.1 seconds.
Given the data in the question;
Since the rock was initially at rest
Initial velocity; [tex]u = 0[/tex]Height or distance of roof from the ground; [tex]s = 6m[/tex]Time taken for the rock to hit the ground; [tex]t = \ ?[/tex]
To determine the time taken for the rock to hit the ground, we use the second equation of motion:
[tex]s = u + \frac{1}{2}at^2[/tex]
Where s is the height or distance, u is the initial velocity, t is time taken and a is acceleration due to gravity( since the rock will be under gravity, [tex]a = g = 9.8m/s^2[/tex] )
We substitute our values into the equation
[tex]6m = 0 + [ \frac{1}{2}\ *\ 9.8m/s^2\ * t^2 ]\\\\6m = 4.9m/s^2 \ * t^2\\\\t^2 = \frac{6m}{4.9m/s^2}\\\\t = \sqrt{\frac{6m}{4.9m/s^2}} \\\\t = 1.1s[/tex]
Therefore, time taken for the rock to hit the ground from the roof top is 1.1 seconds.
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Urgent please!!!!!!!!!!!!!!!!!!!!!!
A program can only create one object of each class.
A. True
B. False
PLESSE HELP ASAP :))))
A car accelerates from 2 m/s to 5 m/s in 1.8 seconds. What is the acceleration of the car?
Answer:
5-2 / 1.8 = 1.66m/s
Explanation:
acceleration = vf-vi / t
vf= 5m/s
vi= 2m/s
t= 1.8 s
What do the words "distance", "force", and "work" have to do with each other?
Answer: the force applied to the object and the distance the object move Work can be calculated with this equation: Work equals Force x Distance.
Explanation:
Fun fact
An apple, potato, and onion all taste the same if you eat them with your nose plugged
Answer:
Fun fact
An apple, potato, and onion all taste the same if you eat them with your nose plugged
Explanation: yes
1. In boxing, fighters wear padded gloves to protect their hands. Which statement explains why a fighter’s hands need protection?
A. There is an equal and opposite velocity impact the hand.
B. There is an equal and opposite acceleration impact the hand.
C. There is an equal and opposite momentum impacting the hand.
D. There is an equal and opposite force impacting the hand.
2. Two balls collide. Under which circumstances will they exert equal and opposite forces on each other?
A. If the sustem is closed
B. in all situations
C. If both are moving at the same speed when they collide
D. if they have the same mass
3. In a closed system, how does an increase in mass change the velocity of an impacted object?
A. Velocity decreases to conserve momentum.
B. Velocity may increase or decrease depending on acceleration.
C. Velocity may increase or decrease depending on force.
D. Velocity increases to conserve momentum.
4. Which of the following provides the correct equation for calculating the momentum of an object?
A. p= mv
B. m= DV
C. F= ma
D. m= vp
5. An object with a mass of 50 kg is moving at a velocity of 2 m/s. What is the momentum of the object?
A. 2 kg*m/s
B. 0.04 kg*m/s
C. 100 kg*m/s
D. 25 kg*m/s
6. A large train car moving along a horizontal track rolls into a smaller stationary train car, causing the cars to attach. Which statement best describes the motion of the cars after the connection?
A. The train cars move in the opposite directions from each other.
B. The train cars move together in the opposite direction the large car was moving.
C. The train cars move together in the direction the large car was moving.
D. The train cars both stay stationary.
7. Which equation correctly represents conservation of momentum for two colliding objects?
A. m1a1+m2a2=0
B. m1v1-m2v2=0
C. m1a1-m2a2=0
D. m1v1+m2v2=0
8. How can the sum of two vectors be found?
A. by drawing the vectors perpendicular to each other
B. by adding the numbers representing the vectors' magnitudes
C. by subtracting the numbers of the vectors' magnitudes
D. by drawing the vectors one right after the other
9. How could a closed system be changed without changing the net force on that system?
A. decrese the acceleration only
B. increase the mass and decrease the acceleration by the same numeric values
C. decrease the acceleration and decrease the mass by the same numeric values
D. increase the mass only
10. Which phrase best describes acceleration?
A. the produce of mass and velocity
B. the change in position over time
C. the product of force and distance traveled
D. the change in velocity over time
11. A ball rolls down a hill at constant velocity. Which of the following conditions must be true?
A. The ball will accelerate as gravity pulls it down the hill.
B. The ball has no net force acting on it.
C. There are no forces acting on the ball.
D. The momentum of the ball increases over time.
12. In an experiment, objects 1 and 2 with masses m1 and m2, respectively, collide with each other. The objects have initial velocities v1i and v2i and final velocities v1f and v2f, respectively. Which result would prove conservation of momentum?
A. m1v1i+m2v2i=m1v1f+m2v2f
B. m1v1i+m1v1f=m2v2i+m2v2f
C. m1v1i+m2v2i+m1v1f+m2v2f>0
D. m1v1i+m2v2i+m1v1f+m2v2f=0
Answer:
1.) D. There is an equal and opposite force impacting the hand
2.) B. In all situations
3.) A. Velocity decreases to conserve momentum
4.) A. p=mv
5.) C. 100 kg*m/s
6.) C. The train cars move together in the direction the large car was moving
7.) D. m1v1+m2v2=0
8.) D. By drawing the vectors one right after the other
9.) B. Increase the mass and decrease the acceleration by the same numeric values
10.) D. The change in velocity over time
11.) B. The ball has no net force acting on it
12.) A. m1v1i+m2v2i=m1v1f+m2v2f
Explanation:
Did the practice
(1) The fighters wear padded gloves to protect their hands because there is an equal and opposite force impacting the hand.
(2) The two balls when collide in a closed system will exert equal and opposite force.
(3) When the mass of the object increases, the velocity of the object will decrease to conserve momentum.
(4) The equation for calculating the momentum of an object is P = mv
(5) The momentum of the ball is 100 kg.m/s
(6) The train cars move together in the direction the large car was moving.
(7) The conservation of momentum of two objects is [tex]m_1v_1 - m_2v_2= 0[/tex]
(8) The sum of two vectors can be found by drawing the vectors perpendicular to each other.
(9) A closed system can be changed without changing the net force on the system by increase the mass and decrease the acceleration by the same numeric values.
(10) Acceleration is defined as the change in velocity over time.
(11) As ball rolls down at constant velocity, the ball has no net force acting on it.
(12) The conservation of momentum of the object is [tex]m_1v_1_i + m_2v_2_i = m_1v_1_f + m_2v_2_f[/tex]
(1)
According to Newton's third law of motion, action and reaction are equal and opposite.
The fighters wear padded gloves to protect their hands because there is an equal and opposite force impacting the hand.
(2)
Based on the principles of conservation of linear momentum, the two balls when collide in a closed system will exert equal and opposite force.
(3)
The principles of conservation of linear momentum is written as;
[tex]m_1u_1 + m_2u_2 = m_1v_1 + m_2v_2[/tex]
when the mass of the object increases, the velocity of the object will decrease to conserve momentum.
(4)
The equation for calculating the momentum of an object is written as;
P = mv
(5)
The momentum of the ball is calculated as follows;
P = mv
P = 50 x 2
P = 100 kg.m/s
(6)
For inelastic collision, the collided two objects move in the same direction after collision usually in the direction of heavier object.
The train cars move together in the direction the large car was moving.
(7)
The conservation of momentum of two objects is written as;
[tex]m_1v_1 = m_2v_2\\\\m_1v_1 - m_2v_2 = 0[/tex]
(8)
The sum of two vectors can be found by drawing the vectors perpendicular to each other.
(9)
A closed system can be changed without changing the net force on the system by increase the mass and decrease the acceleration by the same numeric values.
(10)
Acceleration is defined as the change in velocity over time.
(11)
At constant velocity , acceleration = 0
∑F = ma
∑F = m x 0
∑F = 0
Thus, as ball rolls down at constant velocity, the ball has no net force acting on it.
(12)
The conservation of momentum of the object is written as;
[tex]m_1v_1_i + m_2v_2_i = m_1v_1_f + m_2v_2_f[/tex]
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Joseph drove for 3 hours at the speed of 40 km/h (kilometers per hour) . He changed his speed to 65 km/h for the next 2 hours. How far had Joseph driven in km?
Answer:
Two hundred fifty kilometer 250 km
Do Gamma Rays tend to behave like a particle or a wave?
15% input work is lost due to friction then what is the efficiency of machine?
Answer:
I think 50%
Explanation:
Because the efficiency of a machine is always less than 100%. And efficiency of a machine is 75%.
So, if 15% input work is lost due to friction then efficiency is maybe 50%.
A mover's dolly is used to pull a 115 kg refrigerator up a ramp
into a house. The ramp is 2.10 m long and rises 0.850 m. The
mover exerts a force of 496 N up the ramp. How much work is
spent overcoming friction?
Answer:
84 J
Explanation:
Work by mover:
W = Fd
W = 496 J (2.1 m)
W = 1042 J
Work by dolly and ramp:
W = Fd
W = (mg)d
W = 115 kg (9.8 m/s/s) (0.85 m)
W = 958 J
1042 J - 958 J
= 84 J
The amount of work spent in overcoming friction is 83.65 J.
From the question,
The amount of work spent in overcoming friction = work done by the mover-potential energy of the refrigerator.
This is expressed mathematically as,
W' = Fd-mgh................... Equation 1
Where W' = work spent against friction, F = force applied, d = distance, m = mass of the refrigerator, g = acceleration due to gravity, h = height.
From the question,
Given: F = 496 N, d = 2.10 m, m = 115 kg, h = 0.85 m
Constant: g = 9.8 m/s².
Substitute these values into equation 1
W' = 496(2.1)-(115×9.8×0.85)
W' = 1041.6-957.95
W' = 83.65 J.
Hence, the amount of work spent in overcoming friction is 83.65 J
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A bowling ball is rolling down the lane at a constant velocity of 7.5 m/s. If the bowling ball travels 18 m down the entire lane, how long does it take for the ball to reach the end?
Answer:
The answer is 2.4 sExplanation:
To find how long it took the ball to reach the end we use the formula
[tex]t= \frac{d}{v} \\ [/tex]
where
t is the time
d is the distance
v is the velocity
From the question
d = 18 m
v = 7.5 m/s
We have
[tex]t = \frac{18}{7.5} \\ [/tex]
We have the final answer as
2.4 sHope this helps you
The various different parts of a cell, called organelles, are beneficial to the cell in what way?
Answer:
The various organelles increase the energy used by the cell.
Explanation:
The various different parts of a cell, called as organelles, are beneficial to the cell in different ways such as energy production, protein synthesis, heredity information and packaging of proteins.
What are Organelles?An organelle is a specialized part of the cell which serves a specific purpose within the cell. There are various organelles present within a cell and these organelles also vary depending on what kind of cell we are talking about, whether it be a plant or animal cell such as chloroplast and vacuole.
The different organelles in the cell perform different functions such as ribosomes synthesize proteins, mitochondria synthesize ATP, chloroplast involved in photosynthesis, and nucleus contain heredity information of the cell.
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how do forces work in nature?
The strong force is that force which cause the basic pieces of an atom to hold together. The weak force is radiation; this force is instrumental in things decaying. Electro-magnetism is the charged field which surrounds iron based materials or objects.
Force make objects movable and to change their state. Various kinds of forces in nature balances altogether every processes in nature. The energy we gain or lost is due to some kind of force and resultant displacement.
What is force?Force is an external agent acting on an object to change its state of motion or to deform it. Force is a vector quantity and is characterized by its magnitude and direction. There are various kinds of forces such as gravitational force, magnetic fore, frictional forces, nuclear force etc.
Its due to gravitational force by earth that we are standing on the ground. We experience a weight due to this effect. Similarly the rotating current in the earth core generates the magnetic force of earth.
Every objects need a force to change its state or rest or motion. Similarly, the work done in any fields is the result of any force applied on the system.
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If there is 10% sales tax on a car costing $18,000
How much is the sales tax?
O $180
O $1800
O $1.80
O $800
Answer:
180
Explanation:
i think
How long will it take you to reach the cafeteria if it is 75 m away and you can travel at an average speed of 2 m/s down the stairs?
3.The melting point of lead is 327.5 °C. Which of the following statements is correct? (1 Point) A)Lead is a gas at 280 °C B)Lead is a solid at 310 °C C)Lead is a liquid at 300 °C D)Lead is a solid at 390 °C
Answer:
B)Lead is a solid at 310 °C
Explanation:
The melting point of a substance refers to that temperature in which the substance changes state from solid to liquid. The melting point of a substance, which is usually a temperature value, is that actual temperature the change of state occurs.
According to this question, the melting point of Lead (Pb), which is naturally a solid metal, is 327.5°C. This means that LEAD (Pb) will only change to its liquid state at exactly 327.5°C and above. Therefore, at a temperature of 310°C, which is lower than lead's melting point, Lead element will still be a solid.
Answer: The correct answer is B. Lead is a solid at 310
Explanation:
a car drives 16 m east, then 25 m south, then 16 m west. calculate the distance travelled by car
Answer:
16m + 25m + 16m = 57m
the car travelled 57 m
A sports car has a mass of 1,460kg and accelerates at 2.04 meters per second squared. What is the magnitude of the force acting on the sports car?
Answer:
The answer is 2978.4 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × accelerationFrom the question
mass = 1,460kg
acceleration = 2.04 m/s²
We have
force = 1460 × 2.04
We have the final answer as
2978.4 NHope this helps you
The Indianapolis Motor Speedway has four banked curves, each of which forms a quarter of a circle. Suppose a race car speeds along one of these curves with a constant tangential speed of 75.0 m/s. Neglecting the effects due to the banking of the curve, the centripetal acceleration on the car is 22.0 m/s2. What is the radius of the curve?
Answer:
r = 255.68 m
Explanation:
When a body moves in a circular path, an acceleration, due to constant change in its direction, is developed, known as centripetal acceleration. The centripetal acceleration acts towards the center of the circular path. The formula to calculate the centripetal acceleration is given as follows:
ac = v²/r
where,
ac = centripetal acceleration = 22 m/s²
v = tangential speed = 75 m/s
r = radius of curve = ?
Therefore,
22 m/s² = (75 m/s)²/r
r = (75 m/s)²/(22 m/s²)
r = 255.68 m
What is electricity and where does it come from?
Answer:
it is created power we use everyday
electricity is made of the flow of electrons.
but its made by a generated by a power plant bye electric generators
brainliest?
use your brain :)
What is meant by perfect machine
Answer:
The term ideal machine refers to a hypothetical mechanical system in which energy and power are not lost or dissipated through friction, deformation, wear, or other inefficiencies. Hope this helped :))
Explanation:
An object has a density of 0.755 g/mL. Its volume is 640 mL. What is its mass?
Answer:Density = 7.5 g/ml (By putting the given values.) [ The ratio of the mass to volume is the density, that's why the unit of the density is also the ratio of the unit of mass to the unit of volume. ] Hence, the density of the object is 7
Explanation: Google
You use 35 joules of energy to move a 7 newton box. How far did you move it?
If you picked it straight up, you lifted it 5 meters.
If you moved it horizontally, it could be ANY distance.
Answer:
5
Explanation:
distance = work / force
d = 35 J / 7 N
d = 5 m
Wooden handles on knives do not require maintenance.
TRUE
FALSE
Answer: false
Explanation:
You have to make sure it doesn’t stay wet
The capitary action of water is caused the cohesion of water molecules to different types of molecules and the adhesion of water molecules with other water molecules true or false
Answer:
This is True
Explanation:
I just did this exact unit in bio last week I hope this helps ;)
