Mechanics

Question 1

What is the word equation for speed?

Answer 1

Speed = distance / time

Question 2

What is the symbol equation for speed?

Answer 2

v = d / t

Question 3

What is the equation for velocity?

Answer 3

v = s / t
velocity = changed in DISPLACEMENT / time

Question 4

What is a scalar quantity?

Answer 4

A quantity with magnitude ONLY

Question 5

What is a vector quantity?

Answer 5

A quantity with BOTH magnitude AND direction

Question 6

What is velocity measured in?

Answer 6

ms^-1

Question 7

Define acceleration?

Answer 7

The rate of change of velocity

Question 8

What is the equation for acceleration?

Answer 8

a = (v-u) / t
acceleration = change in velocity / time

Question 9

What is acceleration measured in?

Answer 9

ms^-2

Question 10

How is average speed calculated?

Answer 10

Total distance / total time

Question 11

What is instantaneous speed?

Answer 11

The speed at any particular instant in time of a journey

Question 12

How can instantaneous speed be found?

Answer 12

The gradient of a distance - time graph

Question 13

What is the symbol used for displacement?

Answer 13

s

Question 14

What is the symbol used for distance?

Answer 14

d

Question 15

What is the symbol used for speed?

Answer 15

s

Question 16

What is the symbol used for energy?

Answer 16

e or W

Question 17

What does the gradient of a displacement - time graph tell you?

Answer 17

The velocity

Question 18

How can acceleration be found from a velocity - time graph?

Answer 18

The gradient

Question 19

Other than acceleration, what can a velocity time graph show you and how?

Answer 19

The displacemnent - the area underneath the graph

Question 20

Name the SUVAT equation that does NOT have s in it?

Answer 20

v = u + at

Question 21

How can s = ut + 1/2at^2 be derived?

Answer 21

Combining the equations:
v = u + at
s = 1/2 (v+u) t

s= 1/2(2ut + at^2)
s = ut + 1/2at^2

Question 22

How can v = u + at be derived?

Answer 22

A= (v-u) / t

Rearrange to find v

Question 23

Name the SUVAT equation that does NOT have v in it?

Answer 23

s = ut + 1/2at^2

Question 24

Name the SUVAT equation that does NOT have t in it?

Answer 24

v^2 = u^2 + 2as

Question 25

Name the SUVAT equation that does not have a in it?

Answer 25

s = 1/2(u + v)t

Question 26

What is needed for SUVAT equations to work?

Answer 26

A constant acceleration

Question 27

How many values of SUVAT are needed to find another?

Answer 27

3

Question 28

If an object is being thrown and has left the hand, which direction is the acceleration happening?

Answer 28

The reverse direction ( the ball is not going to speed up after it has left your hand)

Question 29

How must diagram be drawn when showing forces?

Answer 29

All the forces must be joined tip to tail

Question 30

What is a vector?

Answer 30

A quantity with magnitude AND direction

Question 31

What do we use to represent vectors?

Answer 31

Arrows. The direction is the direction and the length is the magnitude

Question 32

What must always be true about the reaction force?

Answer 32

It must be perpendicular to the surface it is acting on

Question 33

What must always be true about a frictional force?

Answer 33

It must be parallel to the surface it is acting on

Question 34

Why would two objects that have 0 vertical velocity fall at the same rate, even if the horizontal velocities were different?

Answer 34

Because the only force acting on both objects is the force due to gravity (ignoring air resistance)

Question 35

What is a moment?

Answer 35

A turning effect on an object around a pivot due to a force being applied

Question 36

How do you calculate moments?

Answer 36

Moment = force x perpendicular distance

Question 37

What two things MUST be true for an object to be in equilibrium?

Answer 37

- The forces are balanced - The net moment is zero

Question 38

What is the centre of gravity?

Answer 38

The point at which all the weight of an object can be considered to act

Question 39

How can you represent forces that do not all act from the same point on an object?

Answer 39

Using a line

Question 40

What is a freebody diagram?

Answer 40

A diagram where an object is shown with all the forces acting on it, ignoring other objects around it

Question 41

What is Newton's First Law?

Answer 41

An object will remain at rest or at constant velocity unless an unbalanced force acts on it

Question 42

What is newton's Second Law?

Answer 42

If an unbalanced force acts on an object its velocity/momentum will change

Question 43

What equation goes with Newton's Second Law?

Answer 43

(net) force = mass x acceleration

Question 44

What is Newton's Third Law?

Answer 44

When a force acts between 2 objects, it will have equal magnitude on both objects but in opposite direction Every action has an equal and opposite reaction