Chapter 9 - Constant Acceleration

Question 1

Displacement-time graphs:

Answer 1

• You can represent the motion of an object on a displacement-time graph. Displacement is always plotted on the vertical axis and time on the horizontal axis
• In these graphs s represents the displacement of an object from a given point in metres and t represents the time taken in seconds

Question 2

Stationary objects on a displacement-time graph:

Answer 2

Question 3

Objects moving with constant speed/velocity on a displacement-time graph:

Answer 3

Question 4

Accelerating objects on a displacement-time graph:

Answer 4

Question 5

What is velocity:

Answer 5

The rate of change of displacement

Question 6

What does the gradient represent on a displacement-time graph?

Answer 6

Velocity

Question 7

Average velocity =

Answer 7

displacement from starting point/time taken

Question 8

Average speed =

Answer 8

total distance travelled/time taken

Question 9

Velocity-time graphs:

Answer 9

• You can represent the motion of an object on a velocity-time graph. Velocity is always plotted on the vertical axis and time on the horizontal axis
• In these graphs v represents the velocity of an object in metres per second and t represents the time taken in seconds

Question 10

Stationary object on a velocity-time graph:

Answer 10

Question 11

An object moving with constant velocity on a velocity-time graph:

Answer 11

Question 12

An object moving with increasing velocity and constant acceleration on a velocity-time graph:

Answer 12

Question 13

What is acceleration?

Answer 13

The rate of change of velocity

Question 14

What does the gradient represent in a velocity-time graph?

Answer 14

Acceleration

Question 15

If the velocity-time graph has a straight line…

Answer 15

the acceleration is constant

Question 16

What does the area between a velocity-time graph and the horizontal axis represent?

Answer 16

The distance travelled

Question 17

How to find the displacement of a velocity-time graph at time t?

Answer 17

For motion in a straight line with positive velocity, the area under the velocity-time graph up to a point t represents the displacement at time t

Question 18

s:
u:
v:
a:
t:

(in relation to velocity-time graphs)

Answer 18

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

Question 19

How to find:

using the velocity-time graph

Answer 19

Question 20

Deriving constant acceleration formulae: eliminating t

Answer 20

Question 21

Deriving constant acceleration formulae: eliminating v

Answer 21

Question 22

Deriving constant acceleration formulae: eliminating u

Answer 22

Question 23

The suvat equations/constant acceleration formulae:

Answer 23

Question 24

Vertical motion under gravity:

Answer 24

The force of gravity causes all objects to accelerate towards the earth. If you ignore the effects of air resistance, this acceleration is constant. The acceleration does not depend on the mass of the object

Question 25

*g*:

Answer 25

An object moving vertically under gravity can be modelled as a particle with a constant downward acceleration of - *g* = 9.8 ms^-2 (answer must be to the same number of d.p. of *g* used)

Question 26

Answer 26