P5

Question 1

What is Work done?

Answer 1

The amount of energy transferred to an object by an external force when it is moved over a certain distance

Question 2

What is the equation for work done?

Answer 2

Work done (S) = force (N) x distance(M)

Question 3

What happens when a car breaks?

Answer 3

Break presses wheel, Force of friction is acting on break and wheel, Kinetic energy of car. Transfers to thermal energy, Temperature of break increase, car slows

Question 4

What happens to elastic materials when we take away the forces acting on them

Answer 4

They return to the original length and shape

Question 5

What is inelastic deformation?

Answer 5

Changes in shape or length in inelastic materials (does not change back)

Question 6

What equation links force spring constant and extension?

Answer 6

Force (N) = spring constant (n/m)x extension(m)

Question 7

What does distance tell us?

Answer 7

How far and object moves (not direction) is a scalar quantity

Question 8

What does displacement tell us?

Answer 8

The distance that an object moves in a straight line from the start to the finish (vector)

Question 9

What equation links, speed and time and distance?

Answer 9

Speed (m) = distance(m)/time (s)

Question 10

What is the typical walking running and cycling speeds

Answer 10

Walking 1.5m/s
Running 3m/s
Cycling 6m/s

Question 11

What is the velocity of an object?

Answer 11

The speed in a given direction

Question 12

What is the velocity of an object at a constant speed travelling in a circle?

Answer 12

Velocity is constantly changing

Question 13

How do you find the gradient of a distance time graph?

Answer 13

Gradient=distance travelled/time taken

Question 14

What does acceleration tell us?

Answer 14

Change in velocity over a given time

Question 15

What is the equation for acceleration ?

Answer 15

Acceleration (m/S(2)= Change in velocity (m/s)/ time(s)

Question 16

What is the acceleration of an object falling towards the Earth?

Answer 16

9.8 m/s. Squared

Question 17

What is terminal velocity?

Answer 17

The maximum speed achieved by an object freely falling through a gas or liquids

Question 18

Why do some objects which fall experience a lower terminal velocity?

Answer 18

Experience more friction due to shape

Question 19

What is Newton’s first law of motion?

Answer 19

-an object remains in the same state of motion unless a resultant force acts on it.

-If the resultant force on an object is zero this means:
a stationary object stays stationary

Question 20

What is Newton second law of motion?

Answer 20

The acceleration of an object is proportional to the resultant force acting on an object and inversely proportional to the mass

Question 21

What’s the equation for force

Answer 21

Force(N) = mass(kg)x acceleration(m/s squared)

Question 22

What is inertia?

Answer 22

The tendency of an object to continue in its state of rest, or in uniform motion unless acted upon by an external force

Question 23

What is inertial Mass?

Answer 23

The inertial mass is a measure of how difficult it is to change the velocity of an object

Question 24

What is Newton’s third law of motion?

Answer 24

Whenever two objects interact, the exert equal and opposite forces

Question 25

What is stopping distance?

Answer 25

The total distance travelled from when the driver first spots the obstruction, and to where the car stops

Question 26

What is thinking distance?

Answer 26

The distance travelled by the car during the drivers reaction time

Question 27

What is breaking distance?

Answer 27

The breaking distance is the distance, the car travels from when the driver applies the brakes to when the car stops

Question 28

How can we measure reaction time?

Answer 28

One person holds a ruler and volunteer places fingers on either side of the bottom, Ruler is dropped volunteer catches, The further the ruler drops the longer the reaction time, Look up the distance in reaction time converter

Question 29

What factors influence thinking distance?

Answer 29

Tiredness, alcohol, drugs and distractions

Question 30

What Factors influence, breaking distance

Answer 30

Wet or icy conditions, less friction Car has worn breaks, less friction Worn brakes

Question 31

Equation links, kinetic, energy, mass and velocity

Answer 31

Kinetic energy = 1/2 mass x velocity

Question 32

What happens during breaking?

Answer 32

Brake pad presses wheel,friction acts between brake and wheel,KE of car is converted to TE in brakes,temperature of brakes increase,car slows as it loses KE

Question 33

What are the dangers of applying a very large braking force if a car is going fast

Answer 33

Car decelerates rapidly. A large amount of kinetic energy is transferred to thermal energy in the brakes causing the brakes to overheat,driver could lose control .

Question 34

What is momentum of a non-moving object?

Answer 34

Zero objects that are not moving, have no momentum

Question 35

How do we calculate momentum?

Answer 35

Momentum = mass(kg) x velocity(m/s)

Question 36

What is the conservation of momentum?

Answer 36

In a closed system, the total momentum before event is equal to the total momentum after an event

Question 37

Skater A bumps into another skater, Skater B. Skater B is stationary. The skaters move off together in a straight line. Explain what happens to the velocity of each of the skaters. Use the idea of conservation of momentum.

Answer 37

-(total) momentum before (collision) = (total) momentum after (collision) -momentum of skater A decreases and momentum of skater B increases -velocity of skater a decreases and velocity if skater b increases

Question 38

scalar quantity

Answer 38

-only has magnitude

Question 39

vector quantity

Answer 39

-has magnitude and direction

Question 40

Two bumper cars with equal momentum crash into each other and stop. Explain why both bumper cars stop after the crash

Answer 40

-the momentum after the crash is 0 -because the momentum of the cars before the collision was equal and opposite -so the total momentum before the collison was 0 -therefore momentum was conserved