Question

A body of mass 0.5kg is moving at a constant velocity of 2ms^-1.to bring it to rest in 2 m the work done is?

Answer 1

m=0.5 kg,u=2 m/s,v=0 m/s(as it is brought to rest),s=2 m
By applying the equation of motion, v²-u²=2as
(0)²-(2)²=2a(2)
=0-4=4a⇒-4=4a⇒a=-4/4=-1 m/s²
F=ma=0.5×(-1)=-0.5 N
W=Fs=(-0.5)×(-1)=0.5 J(Ans.)

Answer 2

Answer:

W = - 1J

Explanation:

m = 0.5kg

u = 2m/s

v = 0m/s

s = 2m

first we have to find acceleration

v^2 - u^2 = 2as

=>  - 2^2 = 2*a*2

=>  - 4/4 = a

=> a =  -1 m/s^2

now, we can to find the force(f)

F = m*a

=>  0.5 * -1

=>  F = -0.5N

last, we are able to find the work done

W = F.S

=>  -0.5 * 2

=>  W = - 1J