Investigating Motion - Core Practical

Equipment

Trolley, 10× 0.1kg masses, string, pulley, ramp, light gates, clamps and clamp stands, balance, piece of card to put on top of trolley, ruler, data logger

Step 1

Set up equipment + allow trolley to move down the ramp at its constant velocity in order to reduce the effects of friction

Step 2

Use the balance to measure mass of trolley with no extra masses added → measure length of card → measure combined mass of trolley with card

Step 3

Mark a line on the ramp just before the first light gate to make sure the trolley travels the same distance each time

Step 4

Add mass to the string and connect string to the trolley

Start with 0.1kg mass hanging on the end of the string and no masses on the trolley

Step 5

Release trolley from rest + record the time it takes for trolley to travel between light gates and the velocity of the trolley at that time

Step 6

Repeat 2 more times

Step 7

Repeat experiment several times while adding masses to the trolley each time until all masses are used up + record time taken and velocity at both gates each time

Step 7

Calculate acceleration of trolley for each recorded value using v-u / t

independent variable

mass of trolley

dependent variable

acceleration

control variable

force

light gates to measure speed

a light gate sends a beam of light from one side of the gate to the detector on the other side → when something passes through the gate, the beam is interrupted → the light gate measures how long the beam was undetected → input length of object and the computer will calculate the speed

light gates to measure acceleration

use an object that interrupts the signal twice in a short period of time e.g. a piece of card with a gap cut in the middle → light gate measures the speed for each section of the objects and uses this to calculate acceleration