8-Motion

Question 1

What is displacement?

Answer 1

How far you are from your starting point, and in which direction

Question 2

What is velocity?

Answer 2

How fast you are going, and in which direction

Question 3

What is the equation for average velocity?

Answer 3

Change in displacement / time taken

Question 4

Why is delta used?

Answer 4

To represent change in

Question 5

What is the area under a velocity-time graph?

Answer 5

The total displacement

Question 6

What is the equation for acceleration?

Answer 6

Change in speed / time taken

Question 7

How do you calculate the acceleration at any point in a velocity-time graph?

Answer 7

Draw a tangent at time t.

Question 8

What are vectors?

Answer 8

Quantities that have both magnitude and direction

Question 9

What are scalar quantities?

Answer 9

Quantities that have magnitude but not direction

Question 10

What is acceleration the rate of change of?

Answer 10

Velocity

Question 11

What is the value of g?

Answer 11

9.8

Question 12

What does iterative mean?

Answer 12

Step-by step

Question 13

What is the main problem with the iterative model?

Answer 13

In reality, when an object is in free fall, the velocity and displacement change all the time, NOT in sudden jumps

Question 14

s = ut + ………?

Answer 14

s = ut + 1/2 at^2

Question 15

v^2 = ………?

Answer 15

V^2 = u^2 + 2as

Question 16

When stopping a car, what are the 2 factors to consider?

Answer 16

Human reaction time and the time taken for the car to come to a halt

Question 17

What does the stopping distance equal?

Answer 17

The breaking distance + thinking distance

Question 18

When a trolley is rolling down a ramp, what is the value of g parallel?

Answer 18

g X sin theta

Question 19

Why does an object reach terminal velocity?

Answer 19

At the beginning of its fall a body has little air resistance retarding its motion. There will also be a force acting downwards due to gravity, its weight. As the air resistance is small the resultant downwards force is comparably large. As the body falls, and accelerates, the air resistance increases so the resultant downwards decreases as does the acceleration. Eventually the air resistance upwards balances with the weight downwards and the resultant force is zero. The body then ceases to accelerate and travels at a constant velocity. Refer to F=ma