The trolley, the mass of which is 200 kg, moves along a horizontal path under the action of a worker’s effort equal to 100N.

The trolley, the mass of which is 200 kg, moves along a horizontal path under the action of a worker’s effort equal to 100N. With what acceleration does the trolley move if the friction force is 50N?

m = 200 kg.

F = 100 N.

Ftr = 50 N.

a -?

According to Newton’s 2 law, the acceleration of a body a is directly proportional to the resultant of all forces Fр that act on the body, and inversely proportional to the mass of the body m: a = Fр / m

The resultant of all forces Fр is called the vector sum of all forces that act on the body.

The force F acts in the horizontal direction, with which the worker pushes the cart, and in the opposite direction, the friction force Ffr.

Fr = F – Ftr.

a = (F – Ftr) / m.

a = (100 N – 50 N) / 200 kg = 0.25 m / s2.

Answer: the trolley is moving with acceleration a = 0.25 m / s2.