Mass, energy and keeping safe in collisions
Answers are for parents and teachers.
1
Make a list of five safety parts or rules for travelling by car, bus or bicycle.
Answers differ: seat belt, child seat, helmet, sitting down in the bus, crossing with a grown-up.
2
Two trucks move at the same speed. One carries sand and the other is empty. Which one has more kinetic energy? Why?
The one with sand, because it has more mass.
3
A moving ball has 15 units of energy. After it hits another ball, the second ball has 11 units and sound has 2. How many units are left for heat?
15 − 11 − 2 = 2 units.
4
Draw a seat belt and an airbag in a car and label what each does.
Belt: holds the body in the seat. Airbag: cushions in a crash.
5
Explain to someone at home why we cross the road with care when a big lorry comes.
A big lorry has a lot of mass and kinetic energy and cannot stop quickly.