Mechanics and Heat

Question 0

What is instantaneous speed?

Answer 0

Instantaneous speed is the average speed over a very short time interval

Question 1

What is the experiment used to find the instantaneous speed?

Answer 1

A light gate connected to an electronic timer is set up on a ramp. A trolley with a mask, measured using a ruler, on it is let go from the top of the ramp. When the mask first intercepts the light gate the electronic timer starts when the mask is no longer intercepting it the electronic timer stops.
We then use the equation:
Length of mask(d)
Time through light gate (t)

Question 2

What is the experiment used to measure instantaneous speed involving one trolley and one light gate?

Answer 2

A ramp is set up with one light gate positioned on it. A trolley with a mask on it is let go from the top of the ramp. When the mask on the trolley first breaks the beam of the light gate the electronic timer connected to it starts and when the mask stops breaking the beam the electronic timer stops. The distance of the mask is measure using a ruler so we can then use the equation:
Speed= length of mask
Time through light gate

Question 3

What is a vector quantity?

Answer 3

A quantity that can be completely described by stating its magnitude and direction

Question 4

What is a scalar quantity?

Answer 4

A quantity that can be completely described by stating its magnitude

Question 5

TRUE OR FALSE

Distance is a vector

Answer 5

FALSE

Distance is a scalar quantity

Question 6

Name a vector quantity?

Answer 6

Displacement

Question 7

What is the difference between distance and displacement?

Answer 7

Displacement is the length measured from the starting point in a straight line and both its magnitude and direction must be stated. Whereas distance is the total length travelled no matter what direction as it is only described by its magnitude.

Question 8

Which is a scalar quantity?

Velocity or speed

Answer 8

Speed is a scalar quantity

Question 9

TRUE OR FALSE

Velocity is a vector quantity

Answer 9

TRUE

Question 10

What is meant by acceleration?

Answer 10

Acceleration is the change in velocity per unit time

Question 11

What is the equation for acceleration?

Answer 11

Acceleration= final velocity-initial velocity

Time

Question 12

What is the sentence that must be written when answering a question involving a speed-time graph?

Answer 12

Distance=area under speed time graph

Question 13

What does a flat velocity time graph dictate about the velocity?

Answer 13

It is constant

Question 14

What does a straight upwards line in a velocity time graph tell you about the velocity?

Answer 14

A constant acceleration

Question 15

What does a straight downwards line on a velocity time graph tell you about the acceleration?

Answer 15

There is a constant deceleration

Question 16

When an object’d speed or direction changes what is it said to be?

Answer 16

Accelerating

Question 17

What determines the motion of an object?

Answer 17

The forces acting upon them

Question 18

What is a force?

Answer 18

The push or pull on an object

Question 19

What three things can forces change of an object

Answer 19

Speed
Direction
Shape

Question 20

What does a newton balance measure?

Answer 20

Force

Question 21

What is meant by the weight of an object?

Answer 21

Weight is the measure of the force due to gravity acting on the object

Question 22

What is weight measured in?

Answer 22

Newtons (N)

Question 23

What is meant by mass?

Answer 23

Mass is the quantity of matter in an object

Question 24

What is mass measured in?

Answer 24

Kilograms (kg)

Question 25

What is meant by gravitational field strength?

Answer 25

Gravitational field strength is the weight per unit mass

Question 26

What is gravitational field strength measured in?

Answer 26

Newtons per kilogram (N/kg)

Question 27

What is the equation involving weight, mass and gravitational field strength?

Answer 27

Weight= mass x gravitational field strength

Question 28

What the gravitational field strength on Earth?

Answer 28

10N/kg

Question 29

TRUE OR FALSE | The greater the mass, the lower the gravity

Answer 29

FALSE | The greater the mass, the greater the gravity

Question 30

TRUE OR FALSE | The shorter the difference between two masses, the lower the force of gravity between them

Answer 30

TRUE

Question 31

What is responsible for keeping satellites in orbit?

Answer 31

Gravitational field strength

Question 32

As the distance from Earth increases what is the consequences on weight?

Answer 32

The weight decreases

Question 33

TRUE OR FALSE | The further away from Earth you go the less your mass becomes

Answer 33

FALSE | Your mass remains the same everywhere

Question 34

What does friction do?

Answer 34

Friction opposes an object, in always the opposite direction of the object

Question 35

What heat loss is there due to friction?

Answer 35

The loss of heat energy and sound energy

Question 36

Name 2 advantages of friction

Answer 36

Prevents the soles of your shoes slipping Allows bike breaks to stop bikes Sand paper on wood Makes a pencil work

Question 37

Name 2 disadvantages to friction

Answer 37

Machine parts rub together and wear away | Machines run slower

Question 38

Name ways in which friction can be prevented

Answer 38

Oiling or greasing the surface Using wooden rollers A layer of wax A layer of air

Question 39

What ways can you increase friction

Answer 39

Choosing surfaces that cause high friction Increasing surface area Increasing air resistance

Question 40

What two factors effect aerodynamic drag?

Answer 40

The shape and size of the object | The speed of the moving object

Question 41

What happens to the aerodynamic drag when the speed increases?

Answer 41

The aerodynamic drag also increases

Question 42

What is streamlining?

Answer 42

The shape of an object which reduces the degree of drag or resistance to motion through a liquid or a gas

Question 43

In what ways do cyclists reduce friction?

Answer 43

Stream lines helmet Thin tyres Crouched cycling position

Question 44

In what ways do parachuters increase friction

Answer 44

The shape of their parachute The light wieght The large surface area

Question 45

TRUE OR FALSE | Force is a scalar quantity

Answer 45

FALSE | Force is a vector quantity as it is completely described by both magnitude and direction

Question 46

What are balanced forces?

Answer 46

Forces which are acting in the same direction but are equivalent

Question 47

What are equivalent forces equal to

Answer 47

No force at all

Question 48

What is Newton's first law?

Answer 48

An object will remain at rest or continue at a constant speed in the same direction unless acted upon by an unbalanced force

Question 49

What effect does increasing the mass have on friction and acceleration?

Answer 49

If the mass where to increase the force of friction would also increase and therefore it will decelerate.

Question 50

What is a Newton?

Answer 50

A Newton is the unit of force required to accelerate a mass of 1kg 1m/s

Question 51

What is meant by the resultant force?

Answer 51

The resultant force is the vector sum of the individual (component) forces acting on an object

Question 52

When do you get a resultant force?

Answer 52

When two or more forces act thy can be replaced by one force which has the same effect, this is the resultant force

Question 53

What is Newtons 2nd law?

Answer 53

If the forces acting on an object are unbalanced then the object will accelerate

Question 54

TRUE OR FALSE | The acceleration is directly proportional to the force

Answer 54

TRUE

Question 55

What is inversely proportional to acceleration?

Answer 55

Mass

Question 56

What is the equation involving force, mass and acceleration?

Answer 56

Force= mass x acceleration

Question 57

What is the acceleration due to gravity equal to??

Answer 57

Gravitational field strength

Question 58

If a projectile is released from very high at the right speed what won't it do?

Answer 58

Hit the ground because it will go into orbit

Question 59

What two independent motions are involved in a projectile?

Answer 59

Constant speed and constant acceleration

Question 60

In which direction is constant speed?

Answer 60

Horizontal

Question 61

Which direction is constant acceleration?

Answer 61

Vertical

Question 62

Why does an object follow a curved path?

Answer 62

Because due to its motion being a combination of a constant horizontal speed and a constant vertical acceleration

Question 63

What is Newton's third law?

Answer 63

If A exerts on B, B exerts an equal but opposite force on A

Question 64

Explain this Newton pair: a golf club striking a golf ball

Answer 64

The golf club exerts a force (action) forwards in the ball and the ball exerts an equal force (reaction) backwards on the club

Question 65

What is the equation involving momentum, mass and velocity

Answer 65

Momentum= mass x velocity

Question 66

TRUE OR FALSE | Momentum is a scalar quantity

Answer 66

FALSE | Momentum is completely described by stating its magnitude and direction

Question 67

What is the law of conservation of linear momentum?

Answer 67

In the absence of net external forces, the total momentum before is equal to the total momentum after

Question 68

What is the equation for a collision when the objects don't stick together?

Answer 68

MaUa+MbUb=MaVa+MbVb

Question 69

What is the equation o a collision when the objects do stick together?

Answer 69

MaUa+MbUb=(Ma+Mb)V

Question 70

What is meant by work done?

Answer 70

Work done is the measure of energy transfer

Question 71

What us temperature

Answer 71

Temperature is the measure of how hot a substance is

Question 72

What is heat

Answer 72

A form of energy

Question 73

TRUE OR FALSE | Heat travels from a hot object to a cd object

Answer 73

TRUE

Question 74

TRUE OR FALSE | The greater he difference of hot and cold the more heat will be transferred

Answer 74

TRUE

Question 75

What is specific heat capacity?

Answer 75

Is the quantity of energy required to change the temperature of 1kg of a substance by 1°C

Question 76

What is latent heat?

Answer 76

The heat energy required to change a substances' state.

Question 77

Is there a change in temperature when a substance changes state?

Answer 77

No

Question 78

What is specific latent heat?

Answer 78

The number of joules of energy required to change the state of 1kg of a substance without a change in temperature