Grade 11 · Practical
Investigation: Newton's second law
Prescribed investigations · about 3 min
Forces on a block resting on a rough incline.Aim: to investigate the relationship between the net force applied to a trolley and its acceleration, keeping mass constant.
Key points- Apparatus: trolley, ticker timer or motion sensor, string, pulley, slotted masses, runway.
- Method: change the hanging mass to change the net force, measuring acceleration each time.
- Plot acceleration (y) against net force (x): a straight line through the origin shows a ∝ Fnet.
- Compensate for friction by tilting the runway until the trolley moves at constant velocity.
- Net force — the resultant of all forces acting.
- Directly proportional — a straight line through the origin.
EXAM TIP
state the controlled variable (total mass of the system) explicitly — investigations always award marks for variable control.