Draw free-body diagrams and find the net force
Grade 11 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.
A 2 kg cart is pushed 12 N to the right while friction pulls 3 N to the left. What is its acceleration, Ari?
A 4 kg cart is pushed 30 N to the right while friction pulls 18 N to the left. What is its acceleration, Bo?
A 2.5 kg cart is pushed 9 N to the right while friction pulls 2 N to the left. What is its acceleration, Esme?
Using the free-body diagram, what is the box's acceleration, Jun?
- 0 m/s², since the up and down forces cancel each other
- 4 m/s² to the right, from the 8 N pull alone
- 2.5 m/s² to the right
- 5.5 m/s² to the right, from (8 + 3) ÷ 2
Using the diagram, how does the 5 kg crate move, Kira?
Free-body diagram (example data): a crate being lowered on a rope of mass 5 kg, with arrows from its center: weight 49 N down; tension 40 N up. Free-body diagram (example data): a crate being lowered on a rope of mass 5 kg, with arrows from its center: weight 49 N down; tension 40 N up. 5 kg tension 40 N weight 49 N - It speeds up downward at 8 m/s², from 40 ÷ 5
- It speeds up upward at 1.8 m/s², since the rope pulls up
- It speeds up downward at 1.8 m/s²
- It moves at a steady speed, since the rope holds it up
Using the diagram, about what is the skydiver's acceleration, Luz?
Free-body diagram (example data): a skydiver of mass 70 kg, with arrows from its center: weight 686 N down; air drag 400 N up. Free-body diagram (example data): a skydiver of mass 70 kg, with arrows from its center: weight 686 N down; air drag 400 N up. Free-body diagram (example data) air drag 400 N weight 686 N skydiver, mass 70 kg - About 9.8 m/s² downward, the acceleration from gravity alone
- About 5.7 m/s² downward, from the 400 N of drag alone
- About 15.5 m/s² downward, from (686 + 400) ÷ 70
- About 4.1 m/s² downward
A box rests on a ramp without sliding. Which set of forces belongs on its diagram, Milo?
- Weight and the normal force, with nothing else on the box
- Weight, the ramp's normal force and friction up the ramp
- Weight, normal force, friction and the ramp's own weight
- Weight, the normal force and a force down the ramp
A rope pulls a wagon forward. Which force does not belong on the wagon's diagram, Noah?
- The wagon's pull on the rope
- The normal force from the ground on the wagon
- The rope's pull on the wagon
- Friction from the ground on the wagon's wheels
A ball launched straight up by a spring toy is still rising. With no air, which forces act on it, Ren?
- Gravity down and a force of its motion up
- No force while it rises, then gravity at the top
- Only gravity, downward
- Gravity down and the launch force up
A cart rolls at a steady speed on a smooth, level track. Which forces act on it, Zee?
- Weight, normal force and a forward force equal to its speed
- Weight and normal force, which cancel
- Weight, normal force and a forward force that keeps it moving
- No forces act, since a moving cart is on its own

