Newton's second law: calculations and data
Grade 11 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
Ari rolls a 3 kg cart east. A string pulls it 30 N east, a spring pushes it 9 N west, and friction drags it 6 N west. What is its acceleration?
Bo rolls a 4 kg cart east. A string pulls it 38 N east, a spring pushes it 6 N west, and friction drags it 4 N west. What is its acceleration?
Esme rolls a 6 kg cart east. A string pulls it 30 N east, a spring pushes it 12 N west, and friction drags it 6 N west. What is its acceleration?
Jun reads the acceleration-force graph of a cart. What is the cart's mass?
- 6 kg: the largest force on the graph
- 2 kg: the slope is 0.5, and mass = 1 ÷ slope
- 0.5 kg: the value of the slope itself, read off the graph
- 3 kg: the largest acceleration on the graph
Kira reads the acceleration-force graph. The same cart gets a net force of 10 N. What acceleration does it have?
- 20 m/s²: the slope of 2 times 10 N
- 5 m/s²: 10 N divided by the slope of 2
- 80 m/s²: 8 times 10 N
- 18 m/s²: 8 plus 10
Luz reads the graph of two carts pulled by the same forces. Which cart has more mass, and by what factor?
- Cart B, twice as massive: slope 0.5 against 1
- Cart A, because its line is steeper
- Cart B, 4 times as massive, as its line is half as steep
- They match, since both lines start at the origin
Read this first
One force on carts of different mass (example data)
mass (kg) acceleration (m/s²) 1 8 2 4 4 2 8 1 Milo reads the table of carts pulled by one force. What is that net force?
- 3.75 N: the average acceleration
- 8 N: mass × acceleration in every row
- 15 N: 1 + 2 + 4 + 8, from the mass column
- 1 N: the last acceleration
Pia wants a straight-line graph of the table. Which plot works?
- Acceleration against mass, which falls in a straight line
- Acceleration against 1 ÷ mass, with a slope of 1 ÷ 8 N
- Acceleration against 1 ÷ mass, with a slope of 8 N
- Mass against acceleration, which rises in a straight line
A 5 kg box on a floor is pushed 30 N east against 12 N of friction. Its weight and the floor's push are 49 N each. What is its acceleration, Ren?
- 3.6 m/s² east: (30 − 12) ÷ 5
- 6 m/s² east: 30 ÷ 5, leaving friction out
- 0 m/s²: the 49 N forces cancel, so it stays still
- 8.4 m/s² east: (30 + 12) ÷ 5
A 4 kg cart rolls east at a steady 2 m/s. A string pulls it 8 N east and friction pulls 8 N west. What is its acceleration, Tala?
- 4 m/s²: (8 + 8) N ÷ 4 kg, from the two forces
- 0 m/s²: the net force is 0 N
- 0.5 m/s²: 2 m/s ÷ 4 kg, using the speed
- 2 m/s²: 8 N ÷ 4 kg, using the 8 N pull alone