Question

A constant net force of 75 N acts on an object initially at rest through a parallel distance of 0.60 m. A) What is the final kinetic energy of the object?B)If the object has a mass of 0.20kg , what is its final speed?

Answer 1

Answer

given,

constant net force = 75 N

distance = 0.60 m

mass = 0.20 Kg

a) by work energy theorem work done is equal to change in kinetic energy.

initial speed = 0 m/s

$W = KE_f - KE_i$

$KE_f - 0 = F .s$

$KE_f = 75 x 0.6$

$KE_f =45\ J$

b) We know.

$KE_f =\dfrac{1}{2}mv^2$

$45=\dfrac{1}{2}\times 0.20 \times v^2$

  v² = 450

  v = 21.21 m/s

the final speed of the object is equal to v = 21.21 m/s