Year 10- motion, forces and radiation

Question 1

What is Newton’s first law?

Answer 1

If the resultant force on an object is zero, the object stays at rest if it is stationary, or it keeps moving with the same speed in the same direction.

Question 2

What does Newton’s first law relate to?

Answer 2

Resultant force

Question 3

What is Newton’s second law?

Answer 3

The acceleration of an object is proportional to the force applied, and inversely proportional to its mass.

Question 4

What does Newton’s second law relate to?

Answer 4

Acceleration

Question 5

What is Newton’s second law as a formula?

Answer 5

F=ma

Question 6

Acceleration is the rate of change of what?

Answer 6

Velocity

Question 7

What is Newton’s third law?

Answer 7

If object A puts a force on object B then B puts an equal and opposite force back on A.

Question 8

What does Newton’s third law relate to?

Answer 8

Action and reaction

Question 9

What does a graph of force against acceleration look like if it is obeying Newtons second law?

Answer 9

A straight line through the origin.

Question 10

What is the formula for momentum in words?

Answer 10

Momentum equals mass times velocity

Question 11

What is the formula for momentum in letters?

Answer 11

p =mv

Question 12

What are the units of momentum?

Answer 12

Kg m/s

Question 13

In a closed system what can you say about momentum?

Answer 13

Momentum is conserved

Question 14

What is a closed system?

Answer 14

A system with no external forces.

Question 15

If an object is moving at a constant velocity what can you say about the resultant force acting on it?

Answer 15

The resultant force is zero.

Question 16

If an object is accelerating or decelerating what can you say about the resultant force acting on it?

Answer 16

The resultant force is non-zero.

Question 17

If an object is changing direction, what can you say about the resultant acting force on it.

Answer 17

The resultant force is non-zero

Question 18

How would you describe the motion of an object is moving in a circle at a constant speed?

Answer 18

Accelerating

Question 19

Why is an object moving in a circle at a constant speed accelerating?

Answer 19

Because its direction so its velocity is changing

Question 20

If an object is falling at terminal velocity, what is the size of the result force?

Answer 20

Zero

Question 21

What is half-life measured in?

Answer 21

Units of time

Question 22

What is half-life?

Answer 22

The average time taken for count rate (or mass) of a radioactive source to fall to half the initial value.

Question 23

What is the formula for count rate after n half-lives?

Answer 23

= initial count rate/(2 to the power n)

Question 24

In a nuclear power station what are control rods used for? (Triple only)

Answer 24

To slow or stop the nuclear reaction.

Question 25

What do we call the nuclear reaction that splits large nuclei? (Triple only)

Answer 25

Fission

Question 26

What do we call the nuclear reaction that combines smaller nuclei? (Triple only)

Answer 26

Fusion

Question 27

What is the name of the reaction that powers the sun? (Triple only) (Triple only)

Answer 27

Nuclear Fusion

Question 28

What is the effect of the running of nuclear power stations on global warming? (Triple only)

Answer 28

No effect

Question 29

Why do nuclear power stations have no effect on global warming? (Triple only)

Answer 29

No hydrocarbon fuels are burned

Question 30

Is nuclear fuel renewable? (Triple only)

Answer 30

No

Question 31

What do we call the dangerous radioactive by product of nuclear power stations? (Triple only)

Answer 31

Nuclear waste.