Water has a high specific heat capacity. Oil has a smaller heat capacity.
The coefficient of static friction between the puck and the surface.
In fact, that coefficient describes exactly how "hard" it is to cause the puck to start moving, if it starts from an idle condition.
Answer is a) the force caused by the wend nag encountering wind and air.
Answer:
the minimum value of torque is 101.7 N-m.
Explanation:
Given that,
Mass of bundle of shingles, m = 30 kg
Upward acceleration of the shingles,
The radius of the motor of the pulley, r = 0.3 m
Let T is the tension acting on the shingles when it is lifted up. It can be calculated as :
T-mg=ma
T=m(g+a)

Let
is the minimum torque that the motor must be able to provide. It is given by :

the minimum value of torque is 
P = m*v
conservation of momentum suggests
initial momentum equals final momentum
mv-initial = mv-final
(0.0010 kg)(50 m/s) = (0.0010 kg + 0.35 kg)v
thus:
v = (0.0010)(50)/(0.351) = 0.142 m/s