10 The figure below shows a 100kg block being released from

10.) The figure below shows a 100-kg block being released from rest. It then takes it 1.3 s to travel 2.0 m to the edge of the table. What is the mass m of the other block? The pulley has no appreciable mass or friction. The kinetic coefficient of friction between block A and the table is 0.3. 100

Solution

Using the equation of motion we have

S = ut + 0.5at^2

2 = 0 + 0.5*a*1.3^2

a = 2.36 m/s2

writing the force equations we have

mg - T = ma ----------------(1)

T - u*100*g = 100a --------(2)

mg - T = 2.36m

T - 0.3*100*g = 100*2.36

adding both equations we have

g(m - 30 ) = 2.36m + 236

9.8m - 294 = 2.36m + 236

m = 71.23 kg

so the mass m of the other block is 71.23 kg