Question

HELP ASAP HELP Two tennis balls of the same mass are served at different speeds: 30 m/s and 60 m/s. Which serve has more kinetic energy and by how much? Defend your answer. *

Answer 1

Answer:

he second ball has four X as much kinetic energy as the first ball

Explain:

Kinetic Energy Is the type of energy an object has due to its state of motion. It's proportional to the square of the speed

m/the mass of the object

v/the speed at which the object moves

The kinetic energy is expressed in Joules (J)

Two tennis balls have the same mass m and are served at speeds v1=30 m/s and v2=60 m/s.

Being m the same for both balls, the second ball has more kinetic energy than the first ball. So there for The second ball has four times as much kinetic energy as the first ball.

Answer 2

Answer:

The second ball has four times as much kinetic energy as the first ball.

Explanation:

Kinetic Energy

Is the type of energy an object has due to its state of motion. It's proportional to the square of the speed.

The equation for the kinetic energy is:

$\displaystyle K=\frac{1}{2}mv^2$

Where:

m = mass of the object

v = speed at which the object moves

The kinetic energy is expressed in Joules (J)

Two tennis balls have the same mass m and are served at speeds v1=30 m/s and v2=60 m/s.

The kinetic energy of the first ball is:

$\displaystyle K_1=\frac{1}{2}m\cdot 30^2$

$\displaystyle K_1=\frac{1}{2}m\cdot 900$

$K_1=450m$

The kinetic energy of the second ball is:

$\displaystyle K_2=\frac{1}{2}m\cdot 60^2$

$\displaystyle K_2=\frac{1}{2}m\cdot 3600$

$K_2=1800m$

Being m the same for both balls, the second ball has more kinetic energy than the first ball.

To find out how much, we find the ratio:

$\displaystyle \frac{K_2}{K_1}=\frac{1800m}{450m}$

Simplifying:

$\displaystyle \frac{K_2}{K_1}=4$

The second ball has four times as much kinetic energy as the first ball.