Forces for y11 mocks

Question 1

what is a force

Answer 1

a push or pull that acts on an object due to an interaction with another object

Question 2

what are some contact forces

Answer 2

-friction
-air resistance
-tension
-normal contact force(force that acts against stationary weight)

Question 3

what are some non contact force

Answer 3

gravitational
magnetic
electrostatic

Question 4

Is air resistance a contact or non-contact force? Explain why.

Answer 4

Air resistance is a contact force. This is because it is due to the physical contact (collisions) between an object and the particles in the air.

Question 5

what are examples of scalars

Answer 5

speed
time
mass
distance

Question 6

what are vectors

Answer 6

velocity
force
momentum
displacement
acceleration

Question 7

Is power a vector or a scalar quantity? Explain your answer.

Answer 7

Power is a scalar quantity because it only has a magnitude (how many watts), it doesn’t have a direction.

Question 8

what are free body diagrams and what do they contain

Answer 8

diagrams that show all the forces acting on an object

Question 9

what is the resultant force

Answer 9

the overall force on an object.

Question 10

for an object to stay still what must happen +an example

Answer 10

more than 1 force must be applied

eg:squishing ball on floor
floor pushes ball up

Question 11

what are the 2 types of deformation(change of shape)

Answer 11

elastic(object returns back to og shape when force is removed)

inelastic(stays deformed)

Question 12

how can we measure extension

Answer 12

measure how springs length changes as downwards force is applied(mass)

Question 13

relation between f and e

Answer 13

f is directly proportional to e

Question 14

higher spring constant

Answer 14

stiffer the material/less elastic

Question 15

what is hookes law

Answer 15

f(N) and e(m) are directly proportional

Question 16

what are the things that can happen to an object if a force is applied

Answer 16

stretch, compress, or bend

Question 17

what is elastic potential energy

Answer 17

energy transferred to an object as it is stretched

Question 18

what is the spring constant/elastic potential energy on a force / extension graph

Answer 18

-gradient on the straight part of the graph
-elastic potential energy

Question 19

what is the limit of proportionality

Answer 19

where the object stops obeying hookes law

Question 20

when a stretched object is released what energy is the epe transferred to

Answer 20

kinetic energy

Question 21

what are the speeds of common objects and average people

Answer 21

walking:1.5m/s
running 3m/s
car 30m/s

Question 22

what is the rate of change in velocity/acceleration

Answer 22

how quickly something speeds up

Question 23

what can acceleration in the 2 equations be assumed as

Answer 23

9.8m/s

Question 24

what is gradient on a distance time graph

Answer 24

speed

Question 25

curved upwards and curved downwards means the tangent will be

Answer 25

upwards:tangent bottom down:tangent above

Question 26

On a distance / time graph, the distance is on the ? -axis and the time is on the ? -axis.

Answer 26

distance:y time:x

Question 27

curve steepens means

Answer 27

object is accelerating

Question 28

what is the gradient of a velocity time graph

Answer 28

acceleration

Question 29

area under curve=

Answer 29

distance travelled

Question 30

how to find distance travelled on velocity time graph

Answer 30

count squares under graph

Question 31

what is terminal velocity

Answer 31

where velocity remains constant

Question 32

what does the size of the air resistance depend on

Answer 32

the number of collisions which depends on the sa of the person and velocity

Question 33

what happens when the diver reaches terminal velocity

Answer 33

resultant force between air resistance is 0

Question 34

what happens when the diver pulls out a parachute at terminal velocity

Answer 34

surface area will increase hugely so air resistance will increase making resultant force be in the upwards direction but as they slow down until resultant force reduces until 0

Question 35

what is newtons 1st law

Answer 35

resultant force is required to move object

Question 36

what is newtons 2nd law

Answer 36

if non 0 force acts on an object it will accelerate rf=ma

Question 37

what is inertia

Answer 37

unless acted on by rf objects at rest will stay at rest and objects in motion will remain at motion

Question 38

what is inertial mass

Answer 38

mass=force/acceleration

Question 39

what is newtons 3rd law

Answer 39

when 2 forces interact the forces they exert on each other are equal and opposite

Question 40

what is the force exerted on you if you push a box

Answer 40

normal contact force

Question 41

what is the energy stored in a force extension graph

Answer 41

the area under the graph

Question 42

what is the moment

Answer 42

turning effect of a force

Question 43

moment equation

Answer 43

M(Nm)=f(N)xd(m)

Question 44

what is the distance in moments

Answer 44

perpendicular distance from line of action to the pivot

Question 45

3 ways we can increase moment

Answer 45

larger force longer distance object(eg spanner) pushing at right angles

Question 46

what makes an object balanced and unable to turn

Answer 46

if total anticlockwise moment=total clockwise moment

Question 47

what do moments allow us to do in mechanical devices

Answer 47

they help transmit forces across a distance and get the most out of a small force

Question 48

what do levers do

Answer 48

make it easier for work to be done(eg lift load)

Question 49

how do levers make it easier for us to do work

Answer 49

they increase the distance from the pivot where the force is applied so less force needed for the same moment

Question 50

how do levers affect force and moment

Answer 50

less force needed for the same moment

Question 51

eg of simple levers

Answer 51

long sticks and bars wheelbarrows

Question 52

what do gears do

Answer 52

transmit rotational effect from one place to another

Question 53

what are gears

Answer 53

circular disks with teeth around their edges

Question 54

when gear teeth interlock what happens

Answer 54

turning one causes the other to turn in the opposite direction

Question 55

what is meant by transmitting the turning effect of a force

Answer 55

converting and input force to an output

Question 56

if input and output are on the same side/diff side of pivot what happens

Answer 56

they act in same direction-wheelbarrow they act in opp directions-scissors

Question 57

why is the output force larger than the input

Answer 57

output is closer to the pivot