Two horizontal forces and act simultaneously on a block of mass as it slides in a…

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

Two horizontal forces

F_1

and

F_2

act simultaneously on a block of mass

m

as it slides in a straight line through a displacement

s

F_1

acts in the direction of motion while

F_2

acts opposite to it. Which one of the following expressions gives the change in kinetic energy of the block after the displacement? (a)

\dfrac{(F_1-F_2)s}{2}

(b)

F_1 s

(c)

(F_1 - F_2)s

(d)

(F_1 + F_2)s