Answer: Lightning is seen before thunder is heard" is correct about thunderstorms
Explanation:
A "thunderstorm" is a disturbance in weather that is related with lightning, dense clouds, heavy rain, hail or thunder. During a thunderstorm, lightning is always seen before thunder because the speed at which the light travels is faster than that of sound's speed.
Also, thunder's noise could be heard up to 10 km away from lightning flash. The thunder sound lasts for a few seconds. The thunder makes noise because of the rapid and fast expansion of the heating of the air.
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Answer:
because light is faster than sound
Explanation:
the speed of light is 299 792 458 m / s
and the speed of sound is 343 m / s
: A person walks 10 meters North, the 5 meters South. His displacement is: _____________. His distance is:
Answer:
Displacement = 5 meters North
Distance = 15 meters
Explanation
If he walks 10 meters North than his displacement would be 10 meters North. But since he walked 5 meters South it changes his displacement to 5 meters North because that is how far he is away from his starting point.
Hope this helps
Se dispara una bala con una velocidad de v = 300[m/s] contra un cascarón esférico de papel que gira con MCU respecto a un eje vertical. Sabiendo que el radio del cascarón es de 10[cm]. Calcular la rapidez angular mínima que deberá girar el cascarón para que el proyectil haga únicamente un agujero. La dirección del movimiento de la bala pasa por el centro de la esfera.
Answer:
w = 4.712 10⁻³ rad / s
Explanation:
For this exercise, the time it takes for the bullet to travel the distance of 2R must be equal to the time that the hole must travel half a circle.
Let's start by calculating the time it takes for the bullet, which is going at constant speed.
v = x / t
t = x / v
t = 2R / v
t = 2 0.10 / 300
t = 6.666 10⁻⁴ s
As they ask that a single hole is formed in this time, it must be rotated half a circle, that is, θ =π rad, for which we use the angular scientific relations, where the shell has constant angular velocity
w = θ / t
w = π / 6,666 10⁻⁴
w = 4.712 10⁻³ rad / s
A 70kg man runs at a pace of 4 m/s and a 50g meteor travels at 2 km/s. Which has the most kinetic energy?.
Answer:
the 70kg man
Explanation:
because he has more weight and is moving faster
what can you say about the acceleration of objects falling in a vacuum?
Answer:
The mass, size, and shape of the object are not a factor in describing the motion of the object. So all objects, regardless of size or shape or weight, free fall with the same acceleration. In a vacuum, a beach ball falls at the same rate as an airliner.
Explanation:
ALL objects (regardless of their mass) free fall with the same acceleration - 9.8 m/s/s. This particular acceleration value is so important in physics that it has its own peculiar name - the acceleration of gravity
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Explanation:
longitudinal wave .
they are composed of rarefaction and compression
there is change of pressure variations through medium
there is change in density throughout the medium
they can be propagated in liquid soild and gasses
example sound wave
transverse wave
they are composed of troughs and Crest
there is no pressure variations throughout the medium
there is no change in density
they can propagated in liquid soild but not gases
example light wave
How much will be the net displacement if a car travels 6 km east and then travels 14 km west
4 points
Assume that a scale is in an elevator on Earth.
what force would the scale exert on a 53-kg person
standing on it during the following situations?
(use Fnet = ma and F = mg and g = 10m/s^2)
a. The elevator moves up at a constant speed.
b. It slows at 2.0 m/s^2 while moving upward.
C. It speeds up at 2.0 m/s^2 while moving downward.
d. It moves downward at a constant speed.
Blank 1:
Blank 2:
Blank 3:
★ Remember :
The reading of scale of a man in an elevator :
When the elevator moves upward with acceleration a, R = m(g + a)When the elevator moves downwards with acceleration a , R = m(g - a)When the elevator falls freely, we take a = g so, R = m(g - g) = 0When the lift is at rest or moves with uniform velocity, a = 0, so R = m(g - 0) = mgA). The elevator moves up at a constant speed[tex].[/tex]
∴ Acceleration of elevator = 0
➠ R = mg
➠ 53 × 10
➠ R = 530N
B). It slows at 2m/s² while moving upward.
∴ Acceleration of elevator = -2m/s²
[Negative sign shows that speed decreases with time]
➠ R = m(g + a)
➠ R = 53(10 + (-2))
➠ R = 53 × 8
➠ R = 424N
C). It speeds up at 2m/s² while moving downward.
∴ Acceleration of elevator = 2m/s²
➠ R = m(g - a)
➠ R = 53(10 - 2)
➠ R = 53 × 8
➠ R = 424N
D). It moves downward at constant speed.
∴ Acceleration of elevator = 0
➠ R = mg
➠ R = 53 × 10
➠ R = 530N
Hope It Helps!(a) When the elevator moves up with a constant speed, the force on the scale is 519.4 N.
(b) When the elevator slows down at 2 m/s² while moving up, the force on the scale is 625.4 N
(c) When the elevator speeds up at 2 m/s² while moving down, the force on the scale is 413.4 N.
(d) When the elevator moves down at constant speed, the force on the scale is 519.4 N.
The given parameters;
mass of the person , m = 53 kgThe force that scale must exert on the person is calculated as follows;
F = mg + ma
F = m(a + g)
(a)
When the elevator moves up with a constant speed, the acceleration is zero.
F = m(0 + g)
F = mg
F = 53 x 9.8 = 519.4 N
(b)
When the elevator slows down at 2 m/s² while moving up;
F = m(a + g)
F = 53(2 + 9.8)
F = 625.4 N
(c)
When the elevator speeds up at 2 m/s² while moving down;
F = m(g - a)
F = 53(9.8 - 2)
F = 413.4 N
(d)
when the elevator moves down at constant speed;
F = m(g - a)
F = 53(9.8 - 0)
F = 519.4 N
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Li and Raj are playing football. They take turns trying to run past each other with the football. Li weighs 125 pound and Raj weighs 175 pounds. Li discovers that if he changes direction quickly when running, he can always dodge out of the way before Raj can tackle him.
Why is Li able to avoid Raj’s tackle? Choose the best description.
Answer:
Li has less mass and therefore less inertia, so he can change his motion more easily than Raj.
Explanation:
Answer:
Li has less mass and therefore less inertia, so he can change his motion more easily than Raj.
Explanation:
3The diagram shows three objects that are
moving. A force acts on each object. For each.
say how its movement will change.
Answer:
ball moves forward
direction of moving car is reversed
plane changes the direction
The force on the ball acting to the right may changes its falling to the net. The north-east force acting on the airplane can drag the plane to the eastward direction thus deviates the plane from north. The backward force acting on the car make it hindrance to its forward movement.
What is force?Force is an external agent acts on a body, to deform it or change its state from motion or rest. There are different type of forces such as magnetic forces, gravitational force.
Force accelerates a body to move where, as the mass increases, more force have to apply to accelerate the body. If two forces acting in opposite direction, the will cancel each other in magnitude.
The force acting on the ball makes it prevents from falling and the force acting on the plane can deviates its direction from north to eastwards. The backward force acting on the car decelerates the car from forward movement.
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WILL GIVE BRAINLIEST!!! (100 points) cliff divers in hawaii dive from 65 meter high cliffs. the rocks at the base of the cliff protrude 27 meters beyond the edge of the cliff. which sketch is the correct representation of the problem?
answer asap please:)
choice 3 because the arrow has to be downward for as. and if the divers want to live, the vx has to be going right and not 0 or they would hit the rocks. I hope it's right!
John is riding the bus to the next samuell football game. The bus is traveling to the right at 20 m/s and Jon is walking towards the back (left) of the bus at 5 m/s. What is Jon’s relative velocity to a stationary observer?
Answer:
Vrel_jon's = 15 [m/s] to the right
Explanation:
Relative velocity is defined as the relative motion between two bodies, taking into account the directions of motion.
Relative velocity is defined as the relative motion between two bodies, taking into account the directions of motion. The relative velocity is defined as the algebraic sum of the velocities, if the movements are opposite the vectors are subtracted, as will be done below.
Vrel = 20 - 5 = 15 [m/s]
A person watching Jon sees him moving to the right at a speed of 15 [m/s]
A car can complete a 800 m long lap in 10 s. What is the speed of the car
Answer:
80 mph
Explanation:
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Answer:
178.955mph or 179mph
Explanation:
✨calculator✨
PLEASE HELP!!! I need a good grade!
Answer:
The answer is D. You're Welcome !
A rocket has a mass of 15 kg and travels a distance of 250 meters in 13 seconds before it explodes.
What is the velocity of the rocket?
And
What is the momentum of the rocket?
Answer:
1. Velocity = 19.2m/s
2. Momentum = 288 Kg/ms-¹
Explanation:
1. The velocity of the rocket can be calculated by using the formula:
V = d/t
Where v = velocity/speed (m/s)
d = distance (m)
t = time (s)
Based on the provided information, d = 250m, t = 13s
v = 250/13
v = 19.231
v = 19.2m/s
2. The momentum of the rocket can be calculated thus:
p = m × v
Where;
p = momentum (Kg/ms-¹)
m = mass (kg)
v = velocity (m/s)
Based on the information, we have v= 19.23m/s, m = 15kg
p = 15 × 19.2
p = 288 Kg/ms-¹
Fill in the correct answers. A big wheel with twice the circumference of a small wheel will rotate with ____ the force and ___ the speed of the small wheel.
A) half, twice
B) Three times, half
C) twice, half
D) half, three times
Answer:
C.
Explanation:
""""""" Twice,Half """"""
A big wheel with twice the circumference of a small wheel will rotate with the force and the speed of the small wheel.
C) twice, half
Circumference of WheelA big wheel with twice the circumference of a small wheel will rotate with twice the force and half the speed of the small wheel.
It is the round circle found on the outside angle of the machine.
It is the adjusted barrel or rod-like portion put on the interior of the machine that's connected to the wheel and makes a difference to advance development.
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A player kicks up a ball at an angle θ with the horizontal. The horizontal range is maximum when θ is equal to
Answer:
The horizontal range is maximum when θ is equal to 45°
Explanation:
Projectile Motion
It's known as the type of motion that experiences an object that is projected near the Earth's surface and moves along a curved path exclusively under the action of gravity.
Being vo the initial speed of the object, θ the initial launch angle, and [tex]g=9.8\ m/s^2[/tex] the acceleration of gravity, then the maximum horizontal distance traveled by the object (also called Range) is:
[tex]\displaystyle d={\frac {v_o^{2}\sin(2\theta )}{g}}[/tex]
Since the sine of an angle is bounded between -1 and 1, the maximum range will occur when the sine is 1:
[tex]\sin(2\theta)=1[/tex]
The only angle between 0° and 360° whose sine is 1 is 90°, thus:
[tex]2\theta=90^\circ[/tex]
Solving:
[tex]\theta=45^\circ[/tex]
The horizontal range is maximum when θ is equal to 45°
The horizontal range is maximum for the value of angle equivalent to [tex]45^{\circ}[/tex].
Given data:
The player kicks the ball with an angle [tex]\theta[/tex] with the horizontal.
The given problem is based on the concept and fundamentals of projectile motion. In a projectile motion, the horizontal range is the horizontal distance covered by an object during its trajectory.
The mathematical expression for the horizontal range is given as,
[tex]R = \dfrac{u^{2}sin2 \theta}{g}[/tex]
Here,
R is the horizontal range.
u is the initial speed.
And g is the gravitational acceleration.
Clearly, if we need maximum horizontal range, then we need to have the maximum value of sine. So if,
[tex]\theta =45^{\circ}[/tex]
[tex]sin2 \theta=sin90[/tex] = 1
So the maximum range is,
[tex]R = \dfrac{u^{2}sin(2 \times 45^{\circ})}{g}\\\\R = \dfrac{u^{2} \times sin 90^{\circ}}{g}\\\\R = \dfrac{u^{2}}{g}[/tex]
Thus, we can conclude that the horizontal range is maximum for the value of angle equivalent to [tex]45^{\circ}[/tex].
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A car in front of the school goes from rest to 27 m/s in 3.0 seconds. What is its acceleration (assuming it is constant)?
Answer:
81 miles per hour
Explanation:
To get the answer, you should multiply 27 by 3, you should multiply distance by time to get the speed.
Answer:
9 m/s²
Explanation:
´Acceleration (a) is the change in velocity (Δv) over the change in time (Δt), represented by the equation a = Δv/Δt. This allows you to measure how fast velocity changes in meters per second squared (m/s^2). Acceleration is also a vector quantity, so it includes both magnitude and direction.´
what are three properties of magnets
How much net force is required make a 10 kg box accelerate at a rate of 5 m/s2?
O2N
0 50 N
0 15 N
0 100 N
Why sound needs medium for propagation? A particle oscillates 40 times in one minute what
will be its time period of oscillations.
plz say me the answer
fast I will mark as brainliest
Answer:
ca taode na kadato itoi runa ko
Answer:
Explanation:
Sound needs a material medium for their propagation like solid, liquid or gas to travel because the molecules of solid, liquid and gases carry sound waves from one point to another. Sound cannot progress through the vacuum because the vacuum has no molecules which can vibrate and carry the sound waves.
Frequency= no. of oscillations/time=40/60sec
4/6=0.66
Question 14
1 pts
An object has a mass of 14 grams and a density of 7 g/mL. When placed in water it sinks. What is the
Volume of water displaced?
-28g
-14ml
-98ml
-2ml
Answer:
The answer is 2 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
From the question
mass = 14 g
density = 7 g/mL
So we have
[tex]volume = \frac{14}{7} \\ [/tex]
We have the final answer as
2 mLHope this helps you
Computer-enhanced x-rays are called __________ scans.
A. TMS
B. PET
C. CT
D. MRI
Answer:
I think the answer is C
Explanation:
EDGE 2020
Computer-enhanced x-rays is called as Computed Tomography (CT) scans. Hence option C is Correct.
What is Computed Tomography (CT) scans ?Computed tomography scan is a medical imaging technique used to get images of our body which is under study. Radiographers or radiology technologists are skilled to handle this machine. It is also know as computed axial tomography scan (CAT scan). it is used to get internal images of the body. It uses rotating X-ray tube and a detector.
CT scans are more detailed than standard X-rays. In standard X-rays, a beam of X-ray is triggered at the body, the beam passes through the body and it gets imposed on the photographic plate which is behind the body. Variation in intensity on the photographic film shows the internal structure of the body. it can not give information about internal organs and other structures.
CT scan combines X-ray images taken at different angles around your body and uses computer for processing to create images (slices) of the bones, and blood vessels. CT scan images gives more-detailed information than X-ray.
Hence option C is correct.
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An object is dropped from rest.
What is its instantaneous speed when it has
been in motion for 3 s? The acceleration of
gravity is 9.8 m/s
2
.
Answer in units of m/s.
Answer:
29.4m/s
Explanation:
Given parameters:
Duration of motion = 3s
Acceleration due to gravity = 9.8m/s²
Unknown:
Instantaneous speed = ?
Solution:
Instantaneous speed is the speed at an instant or a particular time.
Since initial speed = 0 because it was at rest, the best motion equation to solve this problem is given as;
V = U + gt
Where V is the instantaneous speed
U is the initial speed
g is the acceleration due to gravity
t is the time taken
Insert the parameters and solve;
V = 0 + 9.8 x 3 = 29.4m/s
if a truck travels 5 kilometres in 10 minutes find the average velocity of the truck?
Answer:
8.33
Explanation:
av= distance travelled /time taken
Describe an experiment the student could do to measure the specific heat capacity of a metal
Answer:
Steps to determine the specific heat capacity.
1. Place a beaker on a balance and press zero.
2. Now add the oil to the beaker and record the mass of the oil.
3. Read the starting temperature of the oil.
4. Connect a joulemeter to the immersion heater.
5. Time for thirty minutes.
6. Read the number of joules of energy that passed into the immersion heater.
7. Read the final temperature of the oil.
8. Use the following formula to calculate the specific heat capacity.
Explanation:
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2. A flower pot falls from a balcony ledge to the sidewalk below. If the flower pot
falls a distance of 30m, find a) the time it takes to hit the sidewalk b) the velocity
when it hits the sidewalk
Answer:
a) 2.5s
b)24.2m/s
Explanation:
a) s = ut +1/2gt^2
Where u=0
Make t the subject and solve
b) v^2=u^2+2gs
Where u =0
Make v the subject and solve
Why is electricity created at peak times not as efficient?
Explanation:
electricity created at peak........
Electronegativity affects the strength of intermolecular forces. A very electronegative atom will create a stronger negative charge . True or false
Answer:
Electronegative atom will create a stronger negative charge is true.
Explanation:
Given that,
Electronegativity affects the strength of intermolecular forces.
We know that,
Electronegativity :
Electronegativity is a ability of an atom, shared electron to itself.
In periodic table,
When we move left to right in period then the electronegativity increases.
When we move up to down in a group then the electronegativity decreases.
We know that,
The intermolecular forces are dipole-dipole interactions which is the strongest intermolecular force of attraction.
If the electronegativity of atom is more, then the atom gain negative charge.
When the attraction force is more in atoms then the electronegative will be more.
Hence, Electronegative atom will create a stronger negative charge is true.
The moon's light comes from
within the moon
the earth
the sun
stars in other galaxies
At speed, the car accelerated at 1.5 acceleration for 6 seconds. What way did the car go during acceleration?
Answer:
The car would be going forward
Explanation:
Acceleration means there is an increase in the rate or speed of something. And this case it is a vehicle.
