Page 3 - Competency Based Worksheet- Friction

6 N No
8 N Yes
a) What is the maximum value of static friction for the box?
b) What happens when the applied force exceeds the static friction?
c) What type of friction acts once the box starts moving?
d) Why didn’t the box move at 6 N?

13. Rolling Friction Under Different Road Conditions
Road Condition Rolling Friction (N)
Dry road 150 N
Wet road 200 N
Gravel road 100 N
Icy road 60 N
a) On which surface does the tire experience the least friction?
b) Which road condition is safest for driving in terms of friction?
c) Arrange the road conditions from least to greatest friction:

NUMERICAL BASED QUESTIONS
14. A wooden box weighing 20 N is kept on a table. The force of friction between the box
and the table is measured to be 6 N.
a) What is the minimum force needed to just move the box?
b) If a force of 10 N is applied, will the box move?
c) If the box moves, what kind of friction will act on it: static or sliding?
d) What will be the net force acting on the box after it starts moving?

15. A student pushes a box with increasing force. The box just starts to move when the
applied force reaches 25 N. After that, a force of 20 N is needed to keep it moving at
constant speed.
a) What is the static friction?
b) What is the sliding friction?
c) Which is greater: static or sliding friction?