Question

the K. E of an object of mass is moving with a velocity of 10 m/s is 25j . what will be kinetic energy . when its velocity halved? what will be it's kinetic energy when its velocity is increased by 5mins​

Answer 1

Answer:

6.25J and 625J

Explanation:

KE = 1/2 * Mass * Velocity^2

PART 1

25J = 1/2 * mass * 10^2

mass = 0.5 kg

Now velocity is halved so

KE 1 = 1/2 * 0.5 * 5^2

= 6.25J

PART 2

KE 2 = 1/2 *0.5 * 50^2

= 625J

Answer 2

Answer:

First we will find the mass of the body

by using the formula

K.E = 1/2 mv^2. ---- (1 equation)

According to question

when velocity is 10m/s

K.E is 25J

so, putting values in equation 1

We get

25= 1/2 m (10)^2

m =0.5

now,

when velocity is reduced by half it means

v/2=v'

10/= 5 m/s

New K.E will be

K.E= 1/2 mv'^2

K.E = 6.25J

According to question

after Increasing the velocity by 5 time

v"= 10* 5 =50

so New K.E will be

using 1 equation

K.E = 1/2 0.5 (50)^2

K.E = 625J