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3 years ago

A tennis ball is hit into the air with a racket. When is the balls kinetic energy the greatest?

Physics

1 answer:

madam [21]3 years ago

3 0

Answer:

Kinetic energy is maximum when the player hits the ball.

Explanation:

Kinetic energy $=\frac{1}{2} mv^2$ , where m is the mass and v is the velocity.

So kinetic energy is proportional to square of velocity.

Velocity is maximum when the player hits the ball.

So kinetic energy is maximum when the player hits the ball.

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An object is projected horizontally at 14.1 m/s from the top of a 195.0 meter cliff.

Roman55 [17]

What does a physical map show?

the names of countries, states, and cities

the history of an area

the geographical features of an area

the rest stops and restaurants in an area

7 0

3 years ago

How far did a frog jump if he travels at a rate of 2.1 m/s for 10 seconds?

Anestetic [448]

Answer:

21 m

Explanation:

The motion of the frog is a uniform motion (constant speed), therefore we can find the distance travelled by using

$d=vt$

where

d is the distance covered

v is the speed

t is the time

The frog in this problem has a speed of

v = 2.1 m/s

and therefore, after t = 10 s, the distance it covered is

$d=(2.1)(10)=21 m$

3 0

3 years ago

You're driving a vehicle of mass 1350 kg and you need to make a turn on a flat road. The radius of curvature of the turn is 71 m

sergey [27]

Answer:

$v=12.65\ m.s^{-1}$

Explanation:

Given:

mass of vehicle, $m=1350\ kg$

radius of curvature, $r=71\ m$

coefficient of friction, $\mu=0.23$

<u>During the turn to prevent the skidding of the vehicle its centripetal force must be equal to the opposite balancing frictional force:</u>

$m.\frac{v^2}{r} =\mu.N$

where:

$\mu=$ coefficient of friction

$N=$ normal reaction force due to weight of the car

$v=$ velocity of the car

$1350\times \frac{v^2}{71} =0.23\times (1350\times 9.8)$

$v=12.65\ m.s^{-1}$ is the maximum velocity at which the vehicle can turn without skidding.

5 0

3 years ago

The property of matter that describes what it is made of

const2013 [10]

Answer:

Miixture

Explanation:

The answer is mixture

4 0

3 years ago

A ball thrown in to the air starts out with an initial upward velocity but eventually slows and stops before falling back to the

Mashutka [201]

Answer:

b) The downward force of gravity

Explanation:

The gravity force has the biggest influence on the deceleration of the ball because no matter how much force you applied on the ball, it will eventually go down again, according to newton's second law:

$\sum F=m.a$

right after you throw the ball, only the force exerted by the gravity will affect the ball (neglecting air resistance):

$m.g=m.a\\a=g$

so the object will eventually be going down again.

8 0

3 years ago