MEDIUM
Lower Secondary Stage 7
IMPORTANT
Earn 100

Using g = 10 N/kg, calculate the mass of an object which weighs 3000 N.

Important Questions on Forces and their Effects

MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 10 - Forces and their Effects>End of chapter review>Q 4
Explain why we lubricate machines with oil.
MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 10 - Forces and their Effects>End of chapter review>Q 5
Why can a hovercraft move much faster than a normal ship?
MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 10 - Forces and their Effects>End of chapter review>Q 6
An ice skater turns in a circle at a steady speed. Draw and label a diagram to name three forces acting on her skate and mark each with an arrow to show its direction.
MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 10 - Forces and their Effects>End of chapter review>Q 7
Explain the direction of Earth’s gravitational force on different sides of the planet, for example at the north and south poles. Why does nobody fall off?
MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 10 - Forces and their Effects>End of chapter review>Q 8
A sky-diver, dropping very fast, opens his parachute just a few hundred metres before reaching the ground. Draw and label a diagram and use it to explain the forces that act when the parachute first opens.
MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 10 - Forces and their Effects>End of chapter review>Q 8
A sky-diver, dropping very fast, opens his parachute just a few hundred metres before reaching the ground. Draw and label a diagram and use it to explain the forces that act just before he lands safely. What is the difference between these forces and the forces that act on him when the parachute first opens?
MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 10 - Forces and their Effects>End of chapter review>Q 9
Dogs pull a sledge over a flat, icy surface. Their pulling force is 240 N forwards. Air resistance is 160 N and friction from the ice is 60 N. Calculate the size and direction of the overall resultant force on the sledge.
MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Student's Book>Chapter 10 - Forces and their Effects>End of chapter review>Q 9
Dogs pull a sledge over a flat, icy surface. Their pulling force is 240 N forwards. Air resistance is 160 N and friction from the ice is 60 N. Explain how you know whether the sledge is speeding up or slowing down.