what phase change occurs as the substance at .75 atm is heated from 0 C to 25 C
Q1. A 130 N horizontal force keeps a 30 kg chair moving at a constant velocity. Find the
coefficient of kinetic friction between the chair and the floor.
The coefficient of kinetic friction between the chair and the floor is 0.442.
The given parameters;
horizontal force on the chair, F = 130 Nmass of the chair, m = 30 kgThe normal force on the chair is calculated as follows;
Fₙ = mg
Fₙ = 30 x 9.8 = 294 N
The frictional force between the chair and the floor is calculated as follows;
Fk = μFₙ
The net force on the chair is calculated as follows;
[tex]\Sigma F_x = 0\\\\F- \mu_k F_n = 0\\\\130 - \mu_k (294) = 0\\\\\mu_k = \frac{130}{294} \\\\\mu_k = 0.442[/tex]
Thus, the coefficient of kinetic friction between the chair and the floor is 0.442.
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im confused on number one
Explanation:
v=?, u=0, a=?, S=22m.
Using the formula, S=ut+½at²
22={0×5}+(½.a.5²)
22=½.a.5²
a=44/25 = 1.76m/s².
Therefore, net force = work done = ma = 48×1.76 = 84.48N.
therefore, power = work done/time = 84.48/5 = 16.896W.
hope this helps you.
Kevin and Kisha are ice skating. Kisha has a mass of 60 kg, and Kevin has a mass of 45 kg. As they face each
other, Kevin pushes off Kisha with a force of 54 N. Assume the friction between the skaters and the ice is
negligible.
t
Determine the magnitude of Kevin's acceleration.
Write your answer to two significant figures.
m/s
m
If Kevin with mass 45kg pushes Kisha with a force of 54N, the magnitude of Kevin's acceleration is 1.2 m/s²
Kisha's mass = 60 kg
Kevin's mass = 45 kg
Kevin pushes off Kisha with a force of 54 N
Since it was Kevin that pushed Kisha, and the required force is 54N, we can look for Kevin's acceleration using the equation below
F = ma
The considered mass is Kevin's mass
54 = 45a
a = 54/45
a = 1.2 m/s²
The magnitude of Kevin's acceleration is 1.2 m/s²
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Zeb was moving his dresser. He pushed with 1000N and the resulting acceleration was 200m/s2. What was its mass?
Answer:
5
Explanation:
Formula for Mass (for this question)
[tex]mass=\frac{Force}{Acceleration}[/tex]
mass= 1000N/200[tex]m^{2}[/tex]=5
(pls do correct me if I have any mistakes it would rlly help others!)
if you hold a heavy weight over your head, the work you do __________.
Answer:
Is zero.
Explanation:
I legit just had this question on my homework.
What is the magnitude of the force that is exerted on a 15 kg mass to give it an acceleration of 5.0 m/s/s?
An object is moving initially with a velocity of 5.6 m/s. After 3.1 s the object's velocity is -2.7 m/s. What is the object's average acceleration during this time
Answer:
-2.68m/s²
Explanation:
To find acceleration use the formula:
acceleration = change in velocity ÷ time
change in velocity = -2.7 - 5.6 = -8.3m/s (final velocity - initial velocity)time = 3.1sSubstitute in the values:
acceleration = -8.3 ÷ 3.1
acceleration = -2.67741.. ≈ -2.68m/s²
Hope this helps!
If the activity of a source is 70 Bq after 2 years, and 35 Bq after 15 years. How long will be until the activity is 8.75 Bq?
Answer:
So if the half-life is two days, four half-lives is 8 days. Suppose a sample has a count rate of 3,200 Becquerel (Bq) at the start, then its count rate after 8 days would be 1/16th of 3,200 Bq = 200 Bq.
a car travels at a uniform speed of 30 km per hour for 30 mins and then at a uniform speed of 60 km per hour for the next 30 minutes calculate the average speed of a car
A drag racer starts at rest and reaches a speed of 386.0 km/h with an average acceleration of 16.5 m/s2. How long does this acceleration take?
Answer:
about 16.5 by-
wait DO UR OWN MATH lol
Explanation:
P1= 100 kPa
V1= 5 L
T1= 300 degrees Kelvin
P2=100 kPa
V2= ? L
T2= 350 degrees Kelvin
Explanation:
using Charles law; since the pressure is constant
V1/T1 = V2/T2
5/300 = V2/350
cross multiply
V2 X 300 = 5 X 350
V2 = 1750/300
V2 = 5.833L
What experiment determines the upper fixed point of a liquid in a glass thermometer
Explanation:
A flask is half filled with water and heated until the water starts boiling.A thermometer is clamped inside the flask without letting it be in contact with waterThe thermometer is left in the steam such that the bulb is heated by the steam at standard atmospheric pressure.As the bulb is heated, the mercury thread rises up and ehre it remains steady for sometime is marked with a light scratch as the upper fixed point(Add diagram )
an open steel can of volume 216 L is filled to the top with gasoline at 13.5 C. when it warms to 36.0 C, how much gas spills over? (don't forget, both the can and the gasoline are expanding.)
[tex]\\ \sf\longmapsto Q=mc\Delta T[/tex]
[tex]\\ \sf\longmapsto c=\dfrac{Q}{m\Delta T}[/tex]
[tex]\\ \sf\longmapsto c=\dfrac{1320}{5.61(274)}[/tex]
[tex]\\ \sf\longmapsto c=\dfrac{1320}{1537.14}[/tex]
[tex]\\ \sf\longmapsto c=0.85J/kgK[/tex]
4.44J (creds to commenter on the post, just making it bigger)
WHAT IS THE VOLUME OF A 5.71 G PLASTIC CUBE THAT HAS A DENSITY OF 1.15 G/CM3
DONT ANSWER i need to find out if it cant float or sink?!
Answer:
p>Whether an object will float or sink is dependent on its density, and on the density of the liquid it is placed in. In the case of water, an object with a density less than 1 g/cm3 will float. The closer its density is to 1 g/cm3, the more of it will sit below the water level.
a.
In what ways do human beings contribute to the greenhouse effect? Select all that apply.
by using renewable energy
b. by driving gas -powered cars
by studying extreme weather events
d. by making things out of plastic
C.
the amount of energy available to do work is called:
Answer:
Gibbs, free energy
Explanation:
An unknown mass is on a flat frictionless surface and a 2 kg object is attached to it with a string going over pulleyt mounted to the end of the table. Acceleration of the 2 kg object is 1.8 m/s^2. What is the mass of the object?
Answer:
Explanation:
F=ma
F in this case is the gravity acting on the 2kg object. Acceleration of gravity is 9.8 m/s^2. SF=ma, so
F = 2kg*(9.8 m/s^2) = 19.6 N
Now use this force to determine the mass of the object on the table:
F=ma
19.6 N (1N=kg*m/s^2) = m*(1.8 m/s^2)
m = 10.89 kg
5. What must occur for an object to exert a contact force on another object?
Answer:
An object must be touching another.
jane pushed a box with 15 N force (an action) what force does the box have on Jane? which law is this?
Answer:
This is Newton’s third law (forces due to friction). There would be 15N being pushed back at Jane.
Explanation:
Newton’s third law states that for every action there is an equal and opposite reaction. So if Jane pushed with a force of 15N, 15N would be pushed back at her. Hope this helps! :)
vector u has a magnitude of 20 and direction of 0°.vector v has amagnitude of 40and a direction of 60°.find the magnitude and direction of the resultant
Addition of vectors:
vector u
has a magnitude of 20 and a direction of 0º with respect to the horizontal, vector v has a magnitude of 40 and a direction of 60º with respect to the horizontal.
a) Find the magnitude and direction of the resultant to the nearest whole
number.
Vector Sum:
The resultant of two vectors is simply the vector sum of the vectors. There are a handful of ways to present the resultant factor; the notation that shows the vector magnitude and direction is called the polar vector notation. An example of a vector presented in polar vector notation is
a∠θ where a is the magnitude and θis the angle that the vector makes with the horizontal axis.
Answer and Explanation:
Let's first present the vectors in rectangular vector notation.
For the vector →u of magnitude 20 and direction 0∘ to the horizontal axis, the vector is →u=^i20.
For the vector →v
of magnitude 40 and direction 60∘ to the horizontal axis, the vector is →v=^i40cos60∘+^j40sin60∘.
The resultant vector →w is the vector sum of the vectors, i.e.
→w=→u+→v
=^i20+^i40cos60∘+^j40sin60∘
=^i(20+40cos60∘)+^j(40sin60∘)
=^i40+^j20√3
For a vector ^ix+^jy, the magnitude of the vector is √x2+y2 and the direction above the horizontal axis is θ=tan−1(yx).
Let's use the formulas:
|→w|∠θ=√(40)2+(20√3)2∠tan−1(20√340)≈52.9∠40.9∘
The magnitude of the vector is about 53 units in the direction 41-degrees above the horizontal axis.
The magnitude of the resultant vector would be 60 units, and its direction will be 0°.
To find the magnitude and direction of the resultant vector when adding vectors u and v, we can use vector addition formulas:
Magnitude of the Resultant Vector (R):
R = √(u^2 + v^2 + 2uv * cosθ)
where:
u = magnitude of vector u (20)
v = magnitude of vector v (40)
θ = angle between vectors u and v (60°)
Plugging in the values:
R = √(20^2 + 40^2 + 2 * 20 * 40 * cos(60°))
≈ √(400 + 1600 + 1600)
≈ √3600
= 60
Direction of the Resultant Vector (θR):
Use the Law of Cosines to find the angle θR between the resultant vector R and vector u:
cosθR = (v^2 + R^2 - u^2) / (2 * v * R)
Plugging in the values:
cosθR = (40^2 + 60^2 - 20^2) / (2 * 40 * 60)
= (1600 + 3600 - 400) / 4800
= 1
Since cos(0°) = 1, we have θR = 0°.
So, the magnitude of the resultant vector is 60 units, and its direction is 0°.
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A student drops a ball off the top of building and records that the ball takes 2.55s to reach the ground. Determine all unknowns and answer the following questions. Neglect drag.
The unknown variables in the model equation for ball's motion include vertical distance traveled by the ball which is 31.86 m and the final velocity of the ball which is 25 m/s.
The given parameter;
time of motion of the ball, t = 2.55 sThe equations that model the motion of the ball is given as follows;
[tex]h = v_0_y + \frac{1}{2} gt^2[/tex]
[tex]v_f = v_0_y + gt[/tex]
All the unknown variables in the equations include;
[tex]v_0_y[/tex] is the initial vertical velocity of the ball, = 0g is the acceleration due to gravity = 9.8 m/s²h is the vertical distance traveled by the ball = ?[tex]v_f[/tex] is the final velocity of the ball = ?The vertical distance traveled by the ball is calculated as follows;
[tex]h = \frac{1}{2} gt^2\\\\h = 0.5 \times 9.8 \times 2.55^2\\\\h = 31.86 \ m[/tex]
The final velocity of the ball is calculated as follows;
[tex]v_f = 0 + 9.8(2.55)\\\\v_f = 25 \ m/s[/tex]
Thus, the unknown variables in the model equation for ball's motion include vertical distance traveled by the ball which is 31.86 m and the final velocity of the ball which is 25 m/s.
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whose geocentric model of the solar system was accepted for 1400 years
Answer:
Plato, Aristotle developed it further and used for 1400 years till Copernicus.
Explanation:
A steel projectile is shot horizontally at 54 m/s from the top of a 357 m tower. How far
from the base of the tower does the projectile hit the ground?
Hi there!
We can begin by solving for the time it takes the projectile to reach the ground.
Use the equation:
[tex]t = \sqrt{\frac{2h}{g}}[/tex]
Plug in the given height:
[tex]t = \sqrt{\frac{2(357)}{9.8}} = 8.536 s[/tex]
Use the equation:
d = vt, to solve for the horizontal distance:
d = (54)(8.536) = 460.944 m
What two things do you need to know to calculate work
Answer:
Work equals to force times distance
Explanation:
the equation would be work=force*distance
Using Newton’s first law of physics, which explains why it is harder to swim in water with a current (like the ocean) than in contained water (like a pool)?
A.
Perpetual motion can only be interrupted by an unbalanced force.
B.
The current will interfere with perpetual motion more than still water.
C.
It takes much more strength to swim if there is a current than in a pool.
D.
Still water is an immovable object, but currents have their own momentum.
Answer:
It isn't A.
Explanation:
I got it wrong with the answer A.
it is harder to swim in water with a current (like the ocean) than in contained water (like a pool) because Still water is an immovable object, but currents have their own momentum. The correct option is D.
What is Newton's first law of motion?Newton's first law of motion, also known as the law of inertia, states that "an object at rest will remain at rest, and an object in motion will remain in motion with a constant velocity unless acted upon by an unbalanced force."
This means that an object will continue to move in a straight line at a constant speed unless an unbalanced force acts upon it. In addition, if an object is at rest, it will remain at rest unless acted upon by an unbalanced force.
The law of inertia can be applied to many situations. For example, if a book is sitting on a table, it will remain at rest until a force is applied to it. Similarly, if a ball is rolling on a flat surface, it will continue to roll at a constant speed in a straight line unless a force, such as friction, slows it down or changes its direction.
This law is fundamental to understanding the behavior of objects in motion, and it forms the basis for the other two laws of motion formulated by Sir Isaac Newton.
Here in the Question,
Swimming in a pool versus swimming in the ocean, the difference lies in the presence of a current in the ocean.
The current in the ocean has its own momentum, and when a swimmer enters the water, they are faced with an additional force that they must overcome to move forward. This means that the swimmer must apply more force and use more energy to overcome the force of the current and move forward in the water.
In still water, on the other hand, there is no external force acting on the swimmer, so they only have to overcome the resistance of the water itself to move forward.
Therefore, The correct answer is D i.e Still water is an immovable object, but currents have their own momentum.
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an empty boat floats in water with 10% of its volume submerged. and when it is loaded with 1200kg , the volume submerged will increase to 70% of the total volume . calculate the mass of the empty boat
Let volume of empty boat be = 100% = 1V
and mass of boat be M
In water 10%, 0.1V of the volume is submerged.
Mass, m of 1200kg increases the submerging from 10%, 0.1V to 70%, 0.7V
M leads to 0.1V boat submerging
boat submerging.
M + 1200kg leads to 0.7V boat submerging.
This is 60%, 0.6 V increase
By comparison
(M+1200kg) * 0.1V = 0.7V * M
0.1M + 120kg = 0.7M
120kg = 0.7M - 0.1M
120kg = 0.6M
M = (120/0.6)kg
M = 200kg.
The mass of the boat is 200kg.
what is the main deterrant to switching to electrically powered cars?
Answer:
Availability of charging
Explanation:
Assuming the car is not a hybrid and your traveling a very long distance far from civilization, you wouldn't be able to charge the car if it runs out of power as no outlets would be around.
a car travels west for 240km in 4 hr what is the car velcity
What does it mean when an
electromagnetic wave has low energy?
A. it has a long wavelength
B. It has a short wavelength
C.it has a short amplitude
D. It has a high frequency
Answer:
A
Explanation:
Low energy photons (such as radio photons) behave more like waves, while higher energy photons (such as X-rays) behave more like particles.
Please give brainliestAnswer:
B. It has a short amplitude.
:)