Which one of these statements is correct?
- Forces are measured in Newtons but have no direction.
- Forces are measured in kilograms but have no direction.
- Forces are measured in kilograms and have a direction.
- Forces are measured in Newtons and have a direction.
Which one of these statements is true?
- Forces always add up regardless of their direction.
- Forces always subtract, regardless of their direction.
- Forces in the same direction add up, but subtract if they are in opposite directions.
- Forces in the same direction subtract, but add up if they are in opposite directions.
Which of these happens when forces on a stationary object are unbalanced?
- The object accelerates in the direction of the bigger force.
- The object acclerated in the direction of the smaller force.
- The object remains stationary, exerting a larger force on the resultant.
- The object moves at right angles to the resultant force.
What happens if balanced forces act on an object travelling at constant speed?
- The object accelerates.
- The object slows down.
- The object carries travelling at constant speed.
- The object has to be stationary for forces to be balanced.
A large cannon ball and a small ball bearing are dropped at exactly the same time from a tower 10 m tall. Which one statement is true?
- The heavier cannon ball accelerates at a larger rate and reaches the ground first.
- Both objects accelerate at the same rate and reach the ground at the same time.
- The lighter ball bearing is smaller, therefore has less air resistance, so it hits the ground first.
- It's a matter of chance which object hits the ground first.
Which one of these statements explains mass and weight?
- Both are the same and measured in kilograms.
- Both are the same and measured in newtons.
- Weight is measured in kilograms while mass is measured in newtons.
- Weight is a force measured in newtons, while mass is the amount of material in an object, measured in kilograms.
Force and acceleration are related by Force =:
- accleration ÷ mass
- mass ÷ acceleration
- mass × acceleration
- mass + acceleration
When a car driver has to stop really quickly, the distance taken consists of:
- the thinking distance only
- the thinking distance added to the braking distance.
- the braking distance only.
- the thinking distance subtracted from the braking distance.
Which one of the following is true about a driver who has taken alcohol or drugs?
- He is much more alert so the thinking distance is less.
- Alcohol makes the leg weak so less force is put on the brake pedal.
- Alcohol is a depressant so his reactions are slowed down, making the thinking distance more.
- Although the thinking distance is more, the braking distance is less because the driver is much more confident.
Which one of these is true of terminal speed?
- The drag caused by the movement through the air balances the weight pulling down.
- The drag caused by the movement through the air is more than the weight pulling down.
- The drag caused by the movement through the air is less than the weight pulling down.
- It is called terminal speed because hitting the ground at this speed will cause fatal injuries.