Question

A boy of mass 40 kg is on a waterslide which slopes at 30° to the horizontal. The frictional force up the slope is 120 N. Calculate the boy’s acceleration down the slope? Take the acceleration of free fall g to be 9.81 m s−2

Answer 1

1.90 `m/s^2`

Explanation:

so,from the above diagram, component of the boy's weight acting downwards along the plane is `mg sin 30` 0r 196.2 N,for which the boy tends to slip downwards.

Now, frictional force acting above along the plane is 120 N

So, net force acting downwards is (196.2-120) N 0r,76.2 N

hene, acceleration of the boy will be (net force / mass)
i.e 1.90 `m/s^2`