Question

20.Two balls are in motion. A 2-kg ball moving at 4m/s and a 4-kg ball moving at 2m/s, which one has greater kinetic energy? a. 2 kg ball moving at 4 m/s c. Both balls have the same KE b. 4 kg ball moving at 2 m/s d. Cannot be determined

Answer 1

Answer:

A

Explanation:

Given that two balls are in motion. A 2-kg ball moving at 4m/s and a 4-kg ball moving at 2m/s, which one has greater kinetic energy? a. 2 kg ball moving at 4 m/s c. Both balls have the same KE b. 4 kg ball moving at 2 m/s d. Cannot be determined

The formula for kinetic energy is :

K.E = 1/2mv^2

A 2-kg ball moving at 4m/s will have kinetic energy of 1/2 × 2 × 4^2

K.E = 16J

and a 4-kg ball moving at 2m/s will have kinetic energy of 1/2 × 4 × 2^2

K.E = 2 × 4

K.E = 8J

which one has greater kinetic energy? Definitely it is a 2 kg ball moving at 4 m/s. Since 16J is greater than 8J. The correct answer is A.

Answer 2

The energy which we obtained from the moving particle is called kinetic energy.  According to the conservation of energy, the energy can neither be created nor be destroyed.

Hence, the formula used in the question is:- $K.E =\frac{1}{2} mv^{2}$ .

• A 2-kg ball moving at 4m/s will have kinetic energy that is $K.E =\frac{1}{2} 2*4^{2} = 16J$  

Therefore, the kinetic energy of the ball moving the 2kg is 16J.

• A 4-kg ball moving at 2m/s will have kinetic energy that is $K.E =\frac{1}{2} 4*2^{2} = 8J$

Hence the Kinetic energy of the ball moving the 4 kg is 8J.

For more information, refer to the link:-

https://brainly.com/question/12669551