The data table below shows the steady horizontal pulling force needed to keep a…
PHYSICS · Multi-part · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
The data table below shows the steady horizontal pulling force needed to keep a plastic block sliding at constant speed over a laboratory bench.
Trial
mass of block (kg)
steady pulling force (N)
1
0.60
0.78
2
0.80
1.04
3
1.20
1.56
The bench is level and the acceleration due to gravity is 9.8m/s2. Assume measurement uncertainties are negligible for the purpose of the calculation.
(a) For each trial, calculate the magnitude of the normal force exerted by the bench on the block.
(b) For each trial, calculate the numerical value of the kinetic-friction coefficient between the plastic and the bench.
(c) Determine a single best estimate for the kinetic-friction coefficient by appropriately combining the three values obtained in part (b). State your result to two significant figures with proper justification.