Question

What is the change in kinetic energy of a 100 kg object that accelerate from 5m/s to 12.5 m/s?

Answer 1

The initial kinetic energy of the object can be calculated using the formula:

KE = 1/2 * m * v1^2

where KE is the kinetic energy, m is the mass of the object, and v1 is the initial velocity.

KE1 = 1/2 * 100 kg * (5 m/s)^2

KE1 = 1250 J

The final kinetic energy of the object can be calculated using the same formula, but with the final velocity v2:

KE2 = 1/2 * 100 kg * (12.5 m/s)^2

KE2 = 7812.5 J

The change in kinetic energy is then:

ΔKE = KE2 - KE1

ΔKE = 7812.5 J - 1250 J

ΔKE = 6562.5 J

Therefore, the change in kinetic energy of the object is 6562.5 J.

Answer 2

K.E = 1/2 M(V^2-U^2)

___________________________________

/ /

/ M = mass

/ V = final velocity

/ U = initial velocity

/ __________________________________/

= 1/2(100Kg) ( ( 12.5m/s )^2 - ( 5m/s) ^2 )

= 50kg ×( (156.25) - (25) ) m^2/s^2

= 50 kg ×131.25 m^2/s^2

= 6562.5 J

so kinitic energy of object is 6562.5 J .