Interactive physics

Make motion obey the numbers

Change distance, time, mass, and forces. Watch speed, motion graphs, acceleration, and energy update—then use the models to solve real situations.

Part 1

Motion laboratory

Average speed is distance divided by time. The same journey can be fast or slow depending on how long it takes.

Distance120 mTime20 s

Average speed6.0 m/s120 ÷ 20

Part 2

Balance the forces

Opposite forces combine into one net force. With mass fixed, a larger net force produces greater acceleration.

Force left

Force right

Mass

Net force: 6 N · right
Acceleration: 3.0 m/s²

← 4 N

2 kg

10 N →

Acceleration: 3.0 m/s² right

Part 3

Energy on a ramp

Gravitational potential energy depends on mass, gravitational field strength, and height: E = mgh. Lowering the object transfers that stored energy.

Mass3 kgHeight5 m

Stored energy: 147 J
Ideal speed at bottom: 9.9 m/s

E = 3 × 9.8 × 5147 J

Part 4

Use the model

Calculate or reason from the interactive relationships before choosing.

Question 1

A cyclist travels 120 m in 20 s. What is the average speed?

Question 2

A 2 kg cart has 10 N right and 4 N left. What is its acceleration?

Question 3

What happens to gravitational potential energy if height doubles while mass stays the same?

Question 4

A runner covers 150 m in 30 s. What is the average speed?

Question 5

A box has 8 N left and 8 N right. What is the net force?

Question 6

The same net force acts on twice the mass. What happens to acceleration?

Question 7

A 3 kg object is 4 m high. About how much potential energy does it store?

Question 8

On a distance–time graph, which line shows the faster motion?

Question 9

A 3 kg cart has 20 N right and 5 N left. What is its acceleration?

Question 10