Year 9 - Forces & Motion

Question 1

Whats makes a force unbalanced?

Answer 1

If the forces on an object are not the same size we say that they are unbalanced. If the forces on an object are the same size, we say the are balanced.

Question 2

What is the definition of speed?

Answer 2

Speed can be measured of how much distance a object moves in a given time. It can be measured be measured in units like: MP/H KM/H M/S CM/S MM/S etc

Question 3

How can you calculate speed?

Answer 3

You can calculate speed using the formula: Distance -/- Time

Question 4

What is a moment of a force & how do we calculate it?

Answer 4

The moment of a force is a measure of its turning effect.

Moment = Force x Distance (from pivot)

Question 5

What are the three classes of lever?

Answer 5

Type 1 - the pivot is between the effort and load.

Type 2 - effort and load are on the same side and the effort is the furthest from the pivot.

Type 3 - effort and load are on the same side and the load is the furthest from the pivot.

Question 6

What is a pulley?

Answer 6

A pulley is a simple machine consisting of a wheel that can turn on an axis with a rope running around it. We use pulleys to lift heavy things. When the number of pulleys increase, the force needed to lift the mass decreases.

Question 7

What is the equation for work done?

Answer 7

The equation for work done is:

Work done x distance moved

Question 8

What is a pendulum

Answer 8

A pendulum is a mass hanging from a fixed pivot that is free to swing.

Question 9

How do we define the time period of a pedulum?

Answer 9

We define the time period of a pendulum as the time it takes to complete one full swing ( oscillation ) and return to its starting point.