Forces

What is your name?

What is the SI unit of force?

• a) Newton meter
• b) Joule
• c) Newton

When forces are equal in size but opposite in direction, they are called:

• a) Unbalanced forces
• b) Frictional forces
• c) Balanced forces

What force keeps us standing upright on Earth's surface?

• a) Magnetic force
• b) Tension force
• c) Gravity

How do you calculate the weight of an object on Earth's surface?

• a) Weight = Mass (kg) x 8 m/s²
• b) Weight = Mass (kg) x 5 m/s²
• c) Weight = Mass (kg) x 10 m/s²

What is the unit of weight?

• a) Kilogram
• b) Newton
• c) Meter

In space, why do astronauts experience weightlessness?

• a) Because there is no air in space.
• b) Because gravity in space is weaker.
• c) Because they are not moving

What is the force that reduces motion due to rough surfaces called?

• a) Tension
• b) Friction
• c) Gravity

What two key forces of friction act upon cars?

• a) Air resistance and magnetic force
• b) Air resistance and friction from the road
• c) Gravity and electric force

What factor reduces friction between the wheels of racing bikes and the road?

• a) Heavier wheels
• b) Wider wheels
• c) Narrow wheels with smoother surfaces