The drawing shows three objects. They are connected by strings that pass over massless and friction-free pulleys. The objects move starting from rest, and the coefficient of kinetic friction between the middle object and the surface of the table is 0.128. (a) What is the acceleration of the three objects? (b) Find the tension in the string attached to the 25.0 kg object. (c) Find the tension in the string attached to the 10.0 kg object. 80.0 kg 10.0 kg 25.0 kg (a) Number Units (b) Number Units (c) Number Units

A sleigh is being pulled horizontally by a train of horses at a constant speed of 8.05 m/s. The magnitude of the normal force exerted by the snow-covered ground on the sleigh is 6.37 103 N. a. If the coefficient of kinetic friction between the sleigh and the ground is 0.23, what is the magnitude of the kinetic friction force experienced by the sleigh? b. If the only other horizontal force exerted on the sleigh is due to the horses pulling the sleigh, what must be the magnitude of this force?

If a single constant force acts on an object that moves on a straight line, the objects velocity is a linear function of time. The equation v = vi + at gives its velocity v as a function of time, where a is its constant acceleration. What if velocity is instead a linear function of position? Assume that as a particular object moves through a resistive medium, its speed decreases as described by the equation v = vi kx, where k is a constant coefficient and x is the position of the object. Find the law describing the total force acting on this object.

A 3.00-kg object is moving in a plane, with its x and y coordinates given by x = 5t2 1 and y = 3t3 + 2, where x and y are in meters and t is in seconds. Find the magnitude of the net force acting on this object at t = 2.00 s.