Motion, Forces & Radiation

loll throwback to stranger things 5 era

What is Newton’s first law?

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.

What does Newton’s first law relate to?

Resultant force

What is Newton’s second law?

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

What does Newton’s second law relate to?

Acceleration

What is Newton’s second law as a formula?

F=ma

Acceleration is the rate of change of what?

Velocity

What is Newton’s third law?

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

What does Newton’s third law relate to?

Action and reaction

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

A straight line through the origin.

What is the formula for momentum in words?

Momentum equals mass times velocity

What is the formula for momentum in letters?

p =mv

What are the units of momentum?

Kg m/s

In a closed system what can you say about momentum?

Momentum is conserved

What is a closed system?

A system with no external forces.

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

The resultant force is zero.

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

The resultant force is non-zero.

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

The resultant force is non-zero..

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

Accelerating

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

Because its direction so its velocity is changing

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

Zero

What is half-life measured in?

Units of time

What is half-life?

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

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

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

In a nuclear power station what are control rods used for?

To slow or stop the nuclear reaction.

What do we call the nuclear reaction that splits large nuclei?

Fission

What do we call the nuclear reaction that combines smaller nuclei?

Fusion

What is the name of the reaction that powers the sun?

Nuclear Fusion

What is the effect of the running of nuclear power stations on global warming?

No effect

Why do nuclear power stations have no effect on global warming?

No hydrocarbon fuels are burned

Is nuclear fuel renewable?

No

What do we call the dangerous radioactive by product of nuclear power stations?

Nuclear waste