P10

Question 1

What does Newtons second law state

Answer 1

-Resultant force (F) is = to mass x acceleration
-inversely proportional to the mass of the object

Question 2

Equation for newtons second law

Answer 2

F=ma
Resultant force = mass x acceleration

Question 3

What is friction

Answer 3

force that resists the sliding or rolling of one solid object over another

Question 4

What can you use to reduce the friction between surfaces

Answer 4

Lubricant

Question 5

What is the most important factor when reducing drag

Answer 5

Keeping the shape of the object stream lined

Question 6

What is drag

Answer 6

The force that acts in the opposite direction to the movement of the object

Question 7

Why does a falling object accelerate

Answer 7

The force of gravity is much more than the frictional force

Question 8

Why do you gradually slow down when you are falling down

Answer 8

Because the friction increases

Question 9

What does it mean by a terminal velocity

Answer 9

When something has reached it’s maximum speed and starts to fall at a steady speed

Question 10

What does terminal velocity depend on

Answer 10

Shape and area of the object

Question 11

How does an object have a lower terminal velocity

Answer 11

If it has a larger surface area

Question 12

What does stopping distance depend on

Answer 12

Thinking distance + braking distance

Question 13

3 things effecting braking distance

Answer 13

• mass of vehicle
• speed of vehicle
• state of vehicle brakes

Question 14

3 things effecting thinking distance

Answer 14

• levels of alertness
• drug / alcohole in system
• distractions (phone)

Question 15

What is momentum

Answer 15

The mass and velocity of a moving object (Vector quantity)

Question 16

Equation for momentum

Answer 16

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

Question 17

What is conservation of momentum

Answer 17

When the total momentum before an event is the same momentum after an event

Question 18

Equation for spring constant

Answer 18

Force = spring constant x extension
F = ke

Question 19

What does the spring constant depend on

Answer 19

The material you are stretching

Question 20

Inertia

Answer 20

The tendancy of sn object to stay at rest or to continue in uniform motion e.g moving at constant velocity

Question 21

Inertial mass=

Answer 21

Force/acceleration

Question 22

What happens to an objects acceleration when the fresultant force increases?

Answer 22

Acceleration increases as well

Question 23

When does velocity increase?

Answer 23

If the resultant force is in the same direction

Question 24

When does velocity decrease?

Answer 24

When resultant force is opposite to the velocity

Question 25

What happens to an object acted on only by gravity?

Answer 25

Accelerates at 10m/s^2

Question 26

Thinking distance:

Answer 26

Distance travelled by the vehicle in the time it takes the driver to react

Question 27

What opposes the driving force of a vehicle?

Answer 27

Friction and air resistance

Question 28

What increases braking distance?

Answer 28

High speed, poor weather, poor vehicle maintainance, poor reaction time

Question 29

Momentum in a closed system:

Answer 29

Before and event is equal to after an event

Question 30

Example of momentum

Answer 30

Skateboard going the opposite way from you

Question 31

How is an object elastic?

Answer 31

If it returns to its original shape when the forces deforming it are removed

Question 32

Stretch tests (pg 130 kerboodle)

Answer 32

1) the spring to be tested is clamped at its upper end. An empty weight hanger is attached to keep it straight
2) the length of the spring is measured using a metre ruler
3) the weight hung is increase by adding one at a time
4) length of the spring is measured each time a weight is added. Should be measured from the same points each time for accurate results

Question 33

How is the weight on the string directly proprtional?

Answer 33

The spring gives a straight line through the origin

Question 34

Hooke’s law: (limit of proportionality)

Answer 34

The extension of a spring is directly proportional to the force applied, as long as its limit is not exceeded