Question

frnds pls answer it fast...

Answer 1

given, mass of body = 5 kg
initially,
momentum = m x u(initial velocity) = 20
= 5 x u = 20
u = 4 m/s
now, a force of F = 5N is applied on body, so
F = ma = 5N
so the acceleration produced in given body will be,
a = F/m = 5/5 = 1 m/s2
now, using 1st eq of motion
(or u can use a=v-u/t)
v = u + at
v = 4 + 1 x 10
v = 14 m/s
now, initial Kinetic energy = 1/2 mu^2
=1/2 x 5 x 16 = 40
final Kinetic energy = 1/2 mv^2
= 1/2 x 5 x 196 = 490
now,
change in Kinetic energy = final K.E - initial K.E
= 490 - 40 = 450J
hope this helps, if still u have problems feel free to ask or msg me
..... :-)

Answer 2

The correct answer is 200J
Hope it helps you friend
Thanks