Download Name: Practice - 5.1 Friction – Part 2 1. Show that the acceleration of

Name: ___________________________
Practice - 5.1 Friction – Part 2
1. Show that the acceleration of any object down an incline where friction behaves simply
(that is, where Ffk = μkFN) is a = g( sin θ – μkcos θ). Note that the acceleration is
independent of mass.
2. Calculate the deceleration of a snow boarder going up a 5.0º slope, assuming the
coefficient of friction for waxed wood on wet snow. Be careful to consider the fact that
the snow boarder is going uphill.
3. A. Calculate the acceleration of a skier heading down a 10.0º slope, assuming the
coefficient of friction for waxed wood on wet snow. Neglect air resistance.
B. Find the angle of the slope down which this skier could coast at a constant velocity.
Neglect air resistance.
4. CHALLENGE: A contestant in a winter sporting event pushes a 45.0-kg block of ice
across a frozen lake as shown.
A. Calculate the minimum force F he must exert
to get the block moving.
B. What is its acceleration once it starts to move, if that force is maintained?
5. CHALLENGE: A contestant is now pulling the block of ice with a rope over his shoulder at
the angle shown.
A. Calculate the minimum force F he must exert to
get the block moving.
B. What is its acceleration once it starts to move, if that force is maintained?
Solutions:
1.
2. 1.8 m/s2
3. A. 0.74 m/s2
B. 5.7o
4. A. 51 N
B. 0.72 m/s2
5. A. 46 N
B. 0.66 m/s2