P10 - Force And Motion

Question 1

Newton’s Second Law

Answer 1

The acceleration of an object is:
• proportional to the resultant force on an object
• inversely proportional to the mass of an object

so resultant force is proportional to the object’s mass multiplied by its acceleration

Question 3

Forces and acceleration key points

Answer 3

The greater the resultant force on an object, the greater the object’s
acceleration.
• The greater the mass of an object, the smaller its acceleration for a given force.
• The resultant force acting on an object is F= m a
• The inertia of an object is its tendency to stay at rest or in
uniform motion

Question 4

What increases breaking distance?

Answer 4

• high speed
• poor weather conditions
• poor vehicle maintenance

Question 5

What increases thinking distance?

Answer 5

• poor reaction time (due to drugs, alcohol, tiredness, using a mobile phone) and high speed both increase the thinking distance

Question 6

Braking force of a vehicle

Answer 6

F = ma

Question 7

Forces and elasticity practical

Answer 7

You can investigate how easily a material or a spring stretches by hanging weights from ittrigure I
The spring to be tested is
clamped atits upper end. An
empty weight hanger is attached to the spring to keep it straight.
• The length of the spring is measured using a metre ruler.
This is its original length.
• The weight hung from the spring is increased by adding
Investigating stretching weights one at a time. The spring stretches each time more weight is hung from it.
• The length of the spring is measured each time a weight is added. The soring should be measured from the same points each time to ensure accurate results. The total weight added and the total length of the spring are recorded in a table.