Question

read through the scenarios below and calculate the predicted change in kinetic energy of the object compared to a 50 kg ball traveling at 10 m/s.


a 50 kg ball traveling at 20 m/s would have _____ kinetic energy.

a 50 kg ball traveling at 5 m/s would have _____ kinetic energy.

a 50 kg ball traveling at 10 m/s would have _____ kinetic energy.

- the same

- 2 times more

- 2 times less

- 4 times more

- 4 times less

Answer 1

The kinetic energy=mv^2/2
1)4 times kore
2)4times less
3)the same

Answer 2

Explanation:

It is known that kinetic energy is half of mass times velocity square.

Mathematically,   K.E = $\frac{1}{2}mv^{2}$

where        m = mass

                  v = velocity

The kinetic energy from which we have to compare shows that mass is 50 kg and v = 10 m/s.

Therefore,      K.E = $\frac{1}{2}mv^{2}$

                             = $\frac{1}{2}50 \times 10^{2}$

                             = 2500 $m/s^{2}$

1).  K. E = $\frac{1}{2}mv^{2}$

            = $\frac{1}{2}50 \times 20^{2}$

            = 10000 $m/s^{2}$

The object has 4 times more kinetic energy compared to a 50 kg ball traveling at 10 m/s.

2). K. E = $\frac{1}{2}mv^{2}$

            = $\frac{1}{2}50 \times 5^{2}$

            = 1250 $m/s^{2}$

The object has 2 times less kinetic energy compared to a 50 kg ball traveling at 10 m/s.

3). K. E = $\frac{1}{2}mv^{2}$

            = $\frac{1}{2}50 \times 10^{2}$

            = 2500 $m/s^{2}$

The object has the same kinetic energy compared to a 50 kg ball traveling at 10 m/s.