A 15-kg block rests on a level,frictionless surface and is attached by a light string to a 10-kg hanging mass where the string passes over a massless frictionless pulley.If g = 9.8 m/s²,what is the tension in the connecting string? A) 65 N B) 17 N C) 59 N D) 37 N

Question

Quizplus · Accepted Answer

Since the surface is frictionless, there is no horizontal or vertical component of the tension force, thus the tension force is simply equal to the weight of the hanging mass: 
Tension = (mass of hanging mass) * g = 10 kg * 9.8 m/s^2 = 98 N
Since the pulley is massless and frictionless, the tension force on both sides of the pulley must be equal, thus the tension force on the block is also 98 N.

A 15-Kg Block Rests on a Level,frictionless Surface and Is