YEAR 9 Speed And Motion

Question 1

What is the equation for speed?

Answer 1

V=x/t

Question 2

What is the equation for acceleration?

Answer 2

a=v-u/t

Question 3

What are scalar quantities?

Answer 3

Scalar quantities are magnitude only. Some examples are speed, gravitational potential energy, distance, mass and kinetic energy.

Question 4

What are vector quantities?

Answer 4

Vectors have both a magnitude and a direction, and some include velocity, force, displacement and weight.

Question 5

Describe acceleration.

Answer 5

If an object is speeding up we say that it is accelerating, and if it slowing down it is decelerating. Acceleration tells us how many metres per second its speed increases by every second, and it is measured in metres per second squared (m/s 2).

Question 6

Describe speed and velocity

Answer 6

Speed is measured in m/s or km/h. Velocity is the speed of an object in a certain direction, and nothing can travel faster than the speed of light.

Question 7

Describe distance time graphs.

Answer 7

A straight line shows an object moving at a constant speed, and the steeper the line, the faster the object is moving. A flat, horizontal line shows a stationary object, and curved lines show if an object is accelerating or decelerating. The steeper the gradient line gets, the faster the object is moving, and if it is getting less steep, the object is lowing down.

Question 8

Describe velocity time graphs.

Answer 8

A straight line slope shows an accelerating object, and the steeper the gradient the greater the acceleration of the object. If the line slopes down it is decelerating, and a flat, horizontal line shows an object moving at a constant speed.