Brainlag PlusThe trolley practical that tests F = ma: variables, light gates, ticker tape or video, a results table, the graph of acceleration against force, and a full method.
What you are finding out
A trolley on a runway is pulled by a string that runs over a pulley to a hanger of slotted masses.
The weight of the hanging masses is the force that accelerates everything. There are two versions.
- Changing the force: move masses one at a time from the trolley to the hanger. The force goes up, but the total mass being accelerated stays the same, so it is a fair test.
- Changing the mass: add masses to the trolley and keep the same hanging mass, so the force stays the same.
- investigation: how does acceleration depend on force?
- independent: the weight of the hanging masses
- dependent: the acceleration of the trolley
- control: the total mass, the runway, its slope and the start position
Before you start, tilt the runway a little until a gently pushed trolley keeps a steady speed. Its weight down the slope then balances friction.
The rest of this lesson and its 11 practice questions are in Plus.
Screen 1 of 5, free to read.
- 11 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards