Collisions and speed
Answers are for parents and teachers.
1
Find a distance of 10 m at home or school with a grown-up. Time how long you take to walk it and work out your speed.
Answers differ. For example 10 m in 8 s: 10 ÷ 8 = 1.25 m/s.
2
A train goes 90 km in 1 hour and a car goes 70 km in 1 hour. Which is faster? By how much?
The train, by 90 − 70 = 20 km/h.
3
Draw a before picture and an after picture of a ball hitting a box. Write one sentence about the energy.
Answers differ. Kinetic energy of the ball passes to the box and some leaves as sound.
4
Name two places near your home where there is a speed limit or a crossing and say why it helps.
Answers differ, for example near a school or a crossing, to reduce speed and keep people safe.
5
A truck takes 5 s on a ramp with 2 books and 3 s with 4 books on the same 6 m track. Which is faster? Work out both speeds.
The 4-book ramp. 6 ÷ 5 = 1.2 m/s and 6 ÷ 3 = 2 m/s.