P5 Forces And Motion

Question 1

What is contact force

Answer 1

When objects physically are physically touching
Eg friction, normal contact force, air resistance, tension

Question 2

What is non contact force

Answer 2

When the objects are not
Eg. Magnetism, electrostatic force, gravity

Question 3

What is a scalar

Answer 3

A quantity (force) that only has magnitude

Question 4

What is a vector

Answer 4

A quantity (force) that has magnitude and direction

Question 5

5 examples of scalars
(D, S, M, E, T)

Answer 5

Distance
Speed
Mass
Energy
Temperature

Question 6

5 examples of vectors
(D, V, A, F, M)

Answer 6

Displacement
Velocity
Acceleration
Force
Momentum

Question 7

Weight is the force that ____ pulls an object down with

Answer 7

GRAVITY

Question 8

Equation linking Weight, Mass and Gravitational Field Strength

Answer 8

Weight (N) = Mass (Kg) x Gfs (N/kg)

Question 9

GFS of earth

Answer 9

9.8 N/kg

Question 10

100 grams = how many Newtons

Answer 10

1

Question 11

Work done means

Answer 11

Energy transferred by a force

Question 12

What is Hooke’s law

Answer 12

Force and extension are directly proportional
Force = Spring Constant x Extension

Question 13

What is the practical for springs .
How to avoid a systematic and a parallax error whilst doing it?

Answer 13

-Add masses onto a spring to change force
-Measure extension of spring with a metre ruler at each weight
-Plot Force (weight) against extension.
-Find the gradient of the graph to find the spring constant
-Avoid systematic error by lining up 0cm with bottom of spring
-Avoid parallax error by getting on eye level when measuring

Question 14

What is the principle of moments

Answer 14

When the sum of clockwise moments = sun of anti-clockwise moments, a system is in equilibrium (will not turn)

Question 15

What is used to increase moments

Answer 15

Gears

Question 16

What causes pressure in water

Answer 16

The weight of the column of water above an object, pushing down on it

Question 17

What causes pressure in a gas

Answer 17

The particles colliding with the walls of the container, exerting a force on them

Question 18

To increase pressure in a gas you can
(3 things)

Answer 18

Decrease volume of container

-Increase concentration (more frequent successful collisions)

Increase the temperature (more frequent collisions, due to faster speed, AND collide with more momentum, so greater force)

Question 19

The higher your altitude, the ___ dense the atmosphere becomes, meaning the ____ the pressure

Answer 19

Less, Lower

Question 20

The gradient of a distance/displacement - time graph gives you the

Answer 20

Speed/velocity

Question 21

The gradient of a speed/velocity - time graph gives you the

Answer 21

Acceleration

Question 22

The area under a speed/velocity-time graph gives you the

Answer 22

Displacement

Question 23

What is the average walking speed

Answer 23

1.5m/s

Question 24

What is the average running speed

Answer 24

3m/s

Question 25

What is the average cycling speed

Answer 25

6m/s

Question 26

S= U= V= A= T=

Answer 26

Displacement(M) Initial velocity(M/s) Final velocity(M/s) Acceleration (M/s^2) Time(s)

Question 27

What is Newtons 1st law

Answer 27

If no resultant force acts on an object, it’s motion will be constant(velocity will not change - terminal velocity)

Question 28

What is Newtons 2nd law

Answer 28

Force (N) = mass (kg) x acceleration (M/s^2)

Question 29

What is Newtons 3rd law

Answer 29

For every action (force) there is an equal and opposite reaction(force)

Question 30

How to do Newtons 2nd law practical

Answer 30

-Accelerate trolley on track with slotted mass on string over pulley -Use light/photo-gates to measure acceleration -Change force by removing masses and placing on the trolley (to keep the total mass of the system the sams) -Plot force against acceleration, gradient = total mass

Question 31

Stopping distance =

Answer 31

Thinking distance + braking distance

Question 32

Thinking distance is affected by

Answer 32

-Speed -Distractions -Alcohol -Drugs -Tiredness

Question 33

Braking distance is affected by

Answer 33

Speed: if velocity doubles , breaking distance quadruples Condition of breaks, tires, road Weather

Question 34

In any collision, TOTAL MOMENTUM is always

Answer 34

Conserved

Question 35

Force is a measure of the rate of ____ of _____

Answer 35

Change of momentum