Question

John dragged a wooden block across a table with 4 different surfaces and the results

of the experiment are shown in the table below.

Type of surface Average force needed (N)
A 105
B 88
C 127
D 94

(a) Arrange in order, starting from the
smoothest surface to the roughest
surface.

In another experiment, John glued
Surface A from the first experiment
onto a ramp and pulled the same
wooden block up the ramp.

(b) Will the force needed to pull the wooden block up the ramp be more than, less than or
the same as 105N? Explain your answer.

Answer 1

If the surface is rough then the average force needed to move the wooden block will be more as the friction between the surfaces will be more.

Hence, the least force will be required on the smoothest surface and the greatest force will be required for the roughest surface.

a) Hence, the order will be: B > D > A > C

b) When the surface is glued then the force of friction will increase. Hence, it will require more force to move the wooden block on the surface. Hence, the more required will be more than 105 N.