Forces

Question 1

Work Done equation

Answer 1

force x distance moved in direction of force

Question 2

Moment equation

Answer 2

force x perpendicular distance from pivot

Question 3

Levers

Answer 3

sun of all clockwise moments about a point = sun of all anti-clockwise moments about a point

Question 4

What is a Gear?

Answer 4

rotating wheel with teeth that interlocks with another wheel
transmits rotational forces

Question 5

Pressure equation

Answer 5

force / area = pa

Question 6

weight equation

Answer 6

mass x gravitational field strength

Question 7

force equation

Answer 7

spring constant x extension

Question 8

pressure equation 2

Answer 8

density x height x gravitational field strength

Question 9

rule about atmospheric pressure

Answer 9

less molecules = fewer collisions = less pressure

Question 10

speed equation

Answer 10

distance / time

Question 11

velocity equation

Answer 11

displacement / time

Question 12

walking, running & cycling velocity’s

Answer 12

walking - 1.5 m/s
Running - 3 m/s
Cycling - 6 m/s

Question 13

velocity is the _____ on a distance time graph

Answer 13

gradient

Question 14

what does SUVAT stand for?

Answer 14

S = displacement (m)
U = initial velocity (m/s)
V = final velocity (m/s)
A = acceleration (m/s)
T = time (s)

Question 15

acceleration equation

Answer 15

change in velocity / time

Question 16

newton’s first law of motion

Answer 16

a body in motion stays in motion at constant velocity and body at rest stays at rest unless acted upon by a net external force

Question 17

newton’s second law of motion

Answer 17

a body accelerates when acted upon by a net external force. the acceleration is proportional to the net force and is in the direction which the net force acts

Question 18

force equation 2

Answer 18

mass x acceleration

Question 19

newton’s third law of motion

Answer 19

for every action there exists an equal and opposite reaction. if A excerpts a force F on B, the. B excerpts a force of -F on A

Question 20

what is stopping distance

Answer 20

thinking distance and braking distance

Question 21

what is braking distance

Answer 21

that distance take. to stop once the brakes are applied

Question 22

momentum equation

Answer 22

mass x velocity

Question 23

what is momentum

Answer 23

the property of a moving object. the larger momentum an object has, the harder it is to stop

Question 24

conservation of momentum

Answer 24

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

Question 25

force equation 3

Answer 25

change in momentum / time

Question 26

what is a scalar quantity?

Answer 26

a physical quantity that only have magnitude (size) e.g. mass and electric charge.

Question 27

what is a vector quantity?

Answer 27

a physical quantity with both magnitude (size) and direction. e.g. force and weight

Question 28

what is a contact and non-contact force? give examples

Answer 28

contact force = force that acts between two objects that are physically touching each other e.g. friction, air resistance, tension, reaction force

non-contact force = force acting between two objects that are not touching each other e.g. gravitational force, electrostatic force, magnetic force

Question 29

what is weight and how do you calculate it?

Answer 29

the force of gravity on a mass

weight = mass x gravitational field strength

Question 30

what is resultant force and how do you calculate it?

Answer 30

a single force that has the same effect as two or more forces acting together

subtract the magnitude of the smaller force from the larger force

Question 31

what are some examples of the forces involved in stretching, bending or compressing an object?

Answer 31

stretching = weight of mass and tension in spring
bending = weight and reaction force
compressing = weight and reaction force

Question 32

why does more than one force need to be applied to an object to change its shape?

Answer 32

a single force would simply cause the object to move in the direction in which the force is applied

Question 33

what is the difference between elastic deformation and inelastic deformation?

Answer 33

if it returns to its original shape after being stretched its elastic if it doesn’t then its inelastic

Question 34

what is the extension of an elastic object directly proportional to?

Answer 34

the force applied (provided that the limit of proportionality is not exceeded)

Question 35

what is the difference between a linear and non-linear relationship between force and extension?

Answer 35

linear = directly proportional

non-linear = not proportional

Question 36

how do you calculate a spring constant from a linear force-extension graph?

Answer 36

the slope of the graph

Question 37

what is the equation for elastic potential energy?

Answer 37

= o.5 x spring constant x extension2

Question 38

how do forces on a system cause a rotation?

Answer 38

the turning effect of the forces causes the object to rotate

Question 39

what is the difference between distance and displacement?

Answer 39

distance is a scalar meaning only magnitude
displacement is a vector meaning both magnitude and direction

Question 40

what is terminal velocity?

Answer 40

the steady speed achieved by an object freely falling through a gas or liquid

Question 41

what is inertia?

Answer 41

an objects resistance to a change in motion

Question 42

what are the dangers caused by large decelerations?

Answer 42

may cause brakes to overheat and driver to lose control of vehicle

Question 43

when a force acts on an object that is moving or unable to move what happens?

Answer 43

a change in momentum occurs