Year 10 Science • AC9S10U05 • Authored homework
Newton’s laws and force analysis
Investigate Newton’s laws of motion, use force diagrams, and analyse the relationship between force, mass and acceleration using F = ma.
Part A
Short-answer questions
State Newton’s first law in your own words.
State Newton’s second law and give the equation that represents it.
State Newton’s third law in your own words.
What is the difference between mass and weight?
A 4 kg trolley accelerates at 2 m/s². Calculate the net force.
A 20 N net force acts on a 5 kg object. Calculate the acceleration.
What does a free-body diagram show?
Explain what is meant by balanced forces.
Explain what is meant by unbalanced forces.
Give one everyday example where friction changes motion.
Part B
Long-answer questions
A 2 kg cart is pulled with a horizontal force of 10 N. Friction is 2 N in the opposite direction. Calculate the net force and acceleration, showing all steps.
Draw or describe a free-body diagram for a book resting on a table. Explain why the book does not accelerate.
Explain how Newton’s first law applies to a passenger wearing a seatbelt when a car suddenly stops.
Compare the acceleration of a 1 kg object and a 5 kg object if the same net force acts on both. Use Newton’s second law in your explanation.
A skateboarder pushes backward on the ground and moves forward. Use Newton’s third law to explain the action-reaction pair.
Design a fair investigation to test how changing force affects the acceleration of a trolley. Include independent variable, dependent variable and controlled variables.
Design a fair investigation to test how changing mass affects acceleration when force is kept constant. Describe how results should be recorded.
Evaluate this claim: “If an object is moving, there must be a force pushing it forward.” Explain why the claim is incomplete or incorrect.
A parachutist reaches terminal velocity. Explain the forces acting and why acceleration becomes zero even though the person is still moving.
Write a full scientific explanation of how force, mass and acceleration are related. Include an equation, one worked example and one real-world application.
Part C
Research and understanding task
Choose a safety technology such as seatbelts, airbags, helmets, crumple zones or sports padding. Explain how Newton’s laws help the technology reduce injury, including force, acceleration, time of impact and evidence from testing or design.