BPSC – Combined Competitive Examination · প্রশ্ন 121
We apply a force of 200 newtons on a wooden box and push it across the floor at constant velocity. The friction force will be:
উত্তর দেখান ও ব্যাখ্যা
উত্তর: (B) 200 N
ব্যাখ্যা
By Newton's first law, zero acceleration means the forces balance: friction = 200 N.
- (A) ভুল
Wrong: at constant velocity net force is zero, so friction equals 200 N.
- (B) সঠিক
Correct: constant velocity means applied force = friction = 200 N.
- (C) ভুল
Wrong: friction cannot exceed the applied force if velocity is constant.
- (D) ভুল
Wrong: not balanced with 200 N.