Static and kinetic friction
Grade 11 Science Worksheet
Circle the best answer, or write your answer on the line.
Ari pushes a 5 kg box with 30 N across a floor with μk = 0.2. With g = 9.8 m/s², what is the box's acceleration?
Bo pushes a 4 kg box with 20 N across a floor with μk = 0.25. With g = 9.8 m/s², what is the box's acceleration?
Esme pushes a 10 kg box with 50 N across a floor with μk = 0.3. With g = 9.8 m/s², what is the box's acceleration?
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Typical friction coefficients (Engineering ToolBox) (published typical values). Columns: surfaces, static, kinetic. ice on ice, 0 °C, 0.1, 0.02; steel on steel, dry, 0.5–0.8, 0.42; rubber on dry asphalt, 0.9, 0.5–0.8.
In the coefficient table, which pair of surfaces slides most easily, Jun?
- Steel on steel
- They slide equally
- Ice on ice
- Rubber on dry asphalt
A 10 kg box has μs = 0.5 with the floor. Milo pushes it with 30 N and it doesn't move. How big is the static friction?
- 49 N, the limit
- 0 N
- 30 N
- 98 N
The same 10 kg box (μs = 0.5) is pushed with 60 N. What happens, Noah?
- It stays still; friction rises to 60 N
- It lifts off the floor
- It starts to slide
- It stays still; friction is 49 N
The same 10 kg box (μs = 0.5) is pushed with 10 N and stays still. How big is the static friction, Pia?
- 10 N
- 0 N
- 5 N
- 49 N, the limit
Ren presses down on a sliding box while it moves. What happens to the friction force?
- It stays the same
- It increases
- It decreases
- It points the other way
Pulling a wagon's handle upward at an angle, instead of straight across, does what to friction, Tala?
- It has no effect
- It increases it
- It removes it
- It reduces it
A box's load is doubled on the same floor. What happens to the kinetic friction, Zee?
- It quadruples
- It doubles
- It halves
- It stays the same
