Static and kinetic friction
Grade 11 Science Worksheet - Challenge Me
Circle the best answer, or write your answer on the line.
Ari pulls a 5 kg box at a constant velocity across a floor with a horizontal pull of 9.8 N. With g = 9.8 m/s², what is μk?
Bo pulls a 6 kg box at a constant velocity across a floor with a horizontal pull of 14.7 N. With g = 9.8 m/s², what is μk?
In the friction graph, what is μk for the block on the board, Jun?
- 3
- 0.3
- 12
- 3.33
Using the friction graph, what friction would a 50 N normal force give, Kira?
Use the picture in question 3.
- 12 N
- 50 N
- 15 N
- 167 N
What does the straight line in the friction graph show, Luz?
Use the picture in question 3.
- Friction equals the normal force
- Friction falls as the normal force grows
- Friction doesn't depend on the normal force
- Friction is proportional to the normal force
Milo says a box at rest on a level floor always feels its full μs N of static friction. Agree or disagree?
- Agree: and kinetic friction is even bigger
- Disagree: it only matches the push
- Agree: static friction sits at its limit
- Agree: μ is the normal force ÷ friction
Noah says it takes more force to keep a box sliding than to get it started. Agree or disagree?
- Agree: friction at rest sits at its limit
- Disagree: static friction is usually larger
- Agree: μ is N ÷ f
- Agree: kinetic friction is usually larger
Which change makes a heavy box easiest to move across a floor, Ren?
- Put it on a cart with wheels
- Press down on it
- Put rubber pads under it
- Stack another box on it
Why does spreading sand on an icy path help, Tala?
- It makes the ice heavier
- It lowers the normal force on the path
- It raises the friction coefficient
- It melts the ice at once
Why do sleds use thin steel runners on snow and ice, Zee?
- Runners remove the normal force
- Runners make the sled heavier
- Steel on ice has a very small μ
- Steel has a very large μ