Question

A body of mass 40kg is resting on a rough horizontal surface and is subjected to a force P, which is just enough to start the motion of the body. If μs=5,μk=0.4,g=10m/s2 and the force P is continuously applied on the body, then the acceleration of the body is

• A. (A) zero
• B. (B) 1 m/s2
• C. (C) 2 m/s2
• D. (D) 2.4 m/s2

Answer 1

Answer: (B)

(B) 1 m/s2

Answer 2

Explanation:
Force P=fm=μs mg (when body is rest)When the body starts moving with acceleration a thenP−fk=maμsmg−μkmg=maa=(μs−μk)g=(05−0.4)10=0.1×10m/s2=1m/s2