Forces, Motion and Pressure MTA

Question 1

What two things does a force arrow show?

Answer 1

1. The length of the arrow shows the size of the force.
2. The direction of the arrow shows the direction of the force.

Question 2

Give some examples of non-contact forces

Answer 2

• Gravitational force
• Electrostatic force
• Magnetic force

Question 3

Give some examples of contact forces

Answer 3

• Friction
• Air resistance
• Tension
• Normal contact force

Question 4

What are the units for:

a) gravitational field strength
b) weight
c) mass

Answer 4

a) N/kg
b) N
c) kg

Question 5

What equation links weight, mass and gravitational field strength?

Answer 5

Weight = mass x gravitational field strength

W = m g

Question 6

What type of energy is stored in a spring that is stretched or compressed?

Answer 6

Elastic potential energy

Question 7

What happens to the temperature of an object experiencing friction?

Answer 7

Temperature increases

Question 8

What is the name of an object that:

a) will return to its original shape after being deformed
b) will not return to its original shape after being deformed

Answer 8

a) elastic
b) inelastic

Question 9

What is the relationship between force and extension of an elastic object?

Answer 9

Directly proportional

Question 10

What happens to air resistance as speed increases?

Answer 10

As speed increases, air resistance increases.

Question 11

What are typical speed values for someone walking, running and cycling (m/s)?

Answer 11

• Walking 1.5 m/s
• Running 3 m/s
• Cycling 6 m/s

Question 12

What is the speed of sound?

Answer 12

340 m/s

Question 13

How many forces need to to be applied to this spring to stretch or compress it?

Answer 13

Two forces (e.g. one at either end)

Question 14

What equation links distance travelled, speed and time?

Answer 14

Distance travelled = speed x time

s = v t

Question 15

Describe the motion in the following distance-time graph at point (a).

Answer 15

a) constant speed

Question 16

Describe the motion of a moving car experiencing balanced forces.

Answer 16

Keep moving at a constant speed

Question 17

Describe the motion of a moving car experiencing unbalanced forces.

Answer 17

The car will change speed (either accelerate or decelerate)

Question 18

Describe the motion of a stationary car experiencing balanced forces.

Answer 18

The car will remain stationary.

Question 19

Describe the motion of a stationary car experiencing unbalanced forces.

Answer 19

The car will accelerate.

Question 20

What are typical everyday speeds for cars, trains and planes?

Answer 20

• Car 25 m/s
• Train 55 m/s
• Plane 250 m/s

Question 21

If your mass on Earth is 50 kg, what would your mass be on the moon?

Answer 21

The same, 50 kg.

Your mass does not change.

Question 22

Name the forces acting on the book.

Answer 22

Weight (downwards)
Normal contact force (upwards)

Question 23

Describe the experiment to investigate how force affects the extension of the spring.

Answer 23

• Measure the starting length of the spring using the ruler.
• Add one 10 g mass, measure the extension of the spring using the ruler.
• Repeat 5 times, each time adding one 10 g mass and measuring the extension of the spring.

Question 24

Name the equipment used to measure forces

Answer 24

Newtonmeter

Question 25

When oil or grease is used to reduce friction, what is this called?

Answer 25

Lubrication