Question

A motorcycle has a kinetic energy of 12001.
How its kinetic energy will change if its
mass becomes thrice and velocity become
halt?​

Answer 1

Answer:

A motorcycle has a kinetic energy of 12001.

How its kinetic energy will change if its

mass becomes thrice and velocity become

halt?

Answer 2

Correct question :-

A motorcycle has a kinetic energy of 12001.How its kinetic energy will change if its mass becomes thrice and velocity become half?​

Answer :-

1)KE_1 = 3(12,000)

2)KE_2 = 12,000/4

Explanation :-

Given :

Kinetic energy of the motorcycle = 12001

To Find :

What will it’s if the kinetic energy if it’s mass becomes thrice and if the velocity become half

Solution :

1) Let's assume that the kinetic energy of a body is K_1 , mass M_1 and velocity be v. Then kinetic energy of the body is given by,

$\sf{}K_1=\bf{\dfrac{1}{2}\times M_1\times v^2......eq.(1)}$

Kinetic energy if it’s mass is thrice,

$\sf{}K_1=\dfrac{1}{2}\times 3\times (M_1)\times v^2$

$\sf{}K_1=3\times \bf{\dfrac{1}{2}\times M_1\times v^2}$

Here,the bold kninetic energy is same as eq (1) kinetic energy,so we will rewrite it as,

$\sf{}K_1=3K.E$

$\sf{}K_1=3(12,000)$

Hence K.E becomes three times the original.

2) Let's assume that the kinetic energy of a body is K_1 , mass m and velocity be V_1. Then then kinetic energy of the body is given by,

$\sf{}K_1=\bf{\dfrac{1}{2}\times m\times (V_1)^2......eq.(1)}$

Kinetic energy if it’s velocity becomes half,

$\sf{}K_1=\dfrac{1}{2}\times m \times \bigg(\dfrac{v}{2}\bigg)^2$

$\sf{}K_1=\dfrac{1}{2}\times m \times \dfrac{v^2}{4}$

Here,the kinetic energy is same as eq (1) kinetic energy, so we will rewrite it as:

$\sf{}\sf{}K_1=\dfrac{K.E}{4}$       [here, K_1 = K_2]

$\sf{}\sf{}K_1=\dfrac{12001}{4}$

Therefore,if the velocity of the body is halved, its kinetic energy is reduced by a factor of 4.