On the Move

Question 1

What does the gradient of a speed time graph represent?

Answer 1

gradient = speed / time = acceleration

Question 2

What does the area under a speed time graph represent?

Answer 2

The distance travelled - work it out by counting the squares!

Question 3

Two balls are released at the same time above a level floor.
•the first ball is dropped vertically
•the second ball is projected horizontally

Explain why the two balls hit the ground at the same time

Answer 3

• each ball has a downward acceleration = g / 9.8(1)ms-2
• ball projected horizontally experiences same downward acceleration as the other ball
• force of gravity does not affect horizontal motion / vertical and horizontal forces are independent
• There is no resistive force to slow the motion in the horizontal direction.

Question 4

What do the terms in the SUVATs represent…

Answer 4

s = displacement
u = initial velocity
v = final velocity
a = acceleration
t = time

Question 5

In projectile motion what assumptions can you always make…

Answer 5

For the horizontal direction…
a = 0 so you can use velocity = distance / time
(you don’t need to use the full SUVATs)

For the vertical direction…
a = 9.81
u = 0 (normally)

The time will be the same for both the vertical and horizontal directions!