Chapter 2: Forces and Motion

Define distance.

It is the measure of how far an object has travelled.

Define time.

It is the measure of how long an object has been travelling for.

Define distance.

It is the measure of how far an object has travelled.

Define time.

It is the measure of how long an object has been travelling for.

Define weight.

It is the gravitational force on an object.

Define upthrust.

It is the upward force from a liquid or gas that makes things float.

Define dynamic.

It is defined as the opposing force that comes into play when one body is actually moving over the surface of another body.

Define friction.

It is the force that opposes the motion of one material sliding past each another.

Define speed.

It is the rate of motion of an object in any direction.

Define tension.

It is the force in a stretched material.

Define air resistance.

It is another type of friction.

What is parallelogram rule?

It is the is method of finding the resultant in situations, where the vectors are not in line.

What is the unit of force?

Newtons (N)

Newton

noted that when the same force acted for the same time on different masses, a large mass would gain less velocity than a smaller one, but the change in "mass x velocity "was the same in every case.

downward pull

It is the from Earth.

acceleration of free fall

G is the (10 metres per second^2)

U

"is the initial velocity and "v "is the final velocity.

What is total kinetic energy?

If a collision is elastic, the total kinetic energy of the moving objects is the same after the collision as before.

What is earth's gravitational field strength?

It is 10 newtons per kilogram.

What does gradient of speed time graph give?

The gradient of the line is numerically equal to acceleration.

What does gradient of distance time graph give?

The gradient of the line is numerically equal to the speed.

What is frictional force?

It is defined as the force that acts between the surfaces when they are at rest with respect to each other.

How is force measured?

It can be measured using a spring balance.

kinetic energy

Moving objects have .

SI unit of force

is Newton (N)

What is meant by uniform acceleration?

It means a constant (steady) acceleration.

State newtons second law of motion.

It is the link between a resultant force and the rate of change of momentum

total kinetic energy

The is less after the collision than before.

NOTE

this is newtons second law

Q

To find the resultant of two vectors (for example, forces of 30 N and 40 N acting at a point O, as in the diagram below)