Question

A block of mass 4.5 kg is free to move along the
X-axis. It is at rest at t = 0. If the force on the
particle varies with time, then its kinetic energy at
t = 4.5 s is
F(N)
4.5 s
3
S
(1) 2.25 J
(3) 5 J
(2) 1.25 J
(4) Zero​

Answer 1

Answer:

Explanation:

ΔP=integrationf.s

ΔP=1/2*3*4+1/2*1.5*(-2)

ΔP=6-1.5

ΔP=4.5

mv=4.5

4.5v=4.5

v=1m/s

K.E=1/2*mv^2

=1/2*4.5*1*1

K.E=2.25J

Answer 2

F=dp/dt

KE=1/2mv*2

KE=p*2/2m