Physics- Forces In Balance

Question 1

What is displacement?

Answer 1

Distance without change in direction

Question 2

What is a scalar quantity and what are aome examples

Answer 2

Physical quantities with size but no direction
Energy
Power
Time
Distance
Speed
Mass

Question 3

What is a vector quantity and what are some examples

Answer 3

Physical quantities with size and direction
Displacement
Force
Acceleration
Weight
Velocity

Question 4

What is the difference between distnce and displacement?

Answer 4

Displacement is distance without a change in direction.
Displacement is a vector quantity, and distance is a scalar quantity

Question 5

What is the difference between speed and velocity

Answer 5

Velocity is speed in a given direction. Velocity is a vector quantity and speed is a scalar quantity.

Question 6

What is the difference between a vector and a scalar quantity

Answer 6

A vector quantity has a direction but a scalar quantity doesn’t even though they both measure physical quantities with size

Question 7

Generally what does it mean to force something?

Answer 7

Push or pull that acts on an object. Force measured in Newtons

Question 8

What exactly is force in physics?

Answer 8

A push or pull in a certain direction that acts on an object

Question 9

If you apply force on an object what different things can happen to that object

Answer 9

Changing shape (stretch or squash)
Changing motion (accelerate/decelerate)
Changing state of rest (start moving)

Question 10

What are some contact forces

Answer 10

Friction
Air resistance
Stretching (tension)

Question 11

What are some non contact forces

Answer 11

Magnetic force
Gravitational force
Electrostatic force

Question 12

What is the difference between a contact and non contact force

Answer 12

Contact forces must touch to interact. If they don’t need to directly touch to interact these are non-contact forces.

Question 13

What is newtons third law of motion and what are some examples

Answer 13

When two objects interact with eachother they exert equal and opposite forces on eachother
Some examples are swimming or sitting on a chair

Question 14

What is friction

Answer 14

Friction is the force exerted by a surface against an Object when it Moves across it.

Question 15

What are the 6 main forces

Answer 15

Gravity
Friction
Thrust
Air resistnce
Reaction
Gravitational pull

Question 16

What is weight

Answer 16

Force of gravity pulling things down, it makes stuff fall or stay on the ground

Question 17

What is upthrust

Answer 17

Pushes things upwards when they are in liquid helps boats so that they dont sink

Question 18

What is friction

Answer 18

Something that forces two things from sliding past eachother, thats why bicycles dont skid

Question 19

What is air resistance

Answer 19

Something that stops things moving through the air. Pushes leaves and parachutes so that they fall slowly

Question 20

What is reaction

Answer 20

Something that stops things from going right through solid objects. When this thing acts on your chair it pushes you upwards so that tou dont fall through it

Question 21

What is thrust

Answer 21

A forward force. From an engine for example

Question 22

What is resultant force

Answer 22

A resultant force is a single force that has the same affect as multiple forces acting on the object.

Question 23

What is a balanced force

Answer 23

When 2 or more forces have the same amount of force but in different directions

Question 24

What is an unbalanced force

Answer 24

When 2 or more forces have different amount of force in different directions.

Question 25

What is the centre of mass

Answer 25

The centre of mass of an object is the point at which its
Weight can be thought of as being a point

Question 26

How can the centre of mass be found on a regular object

Answer 26

Drawing the lines of symmetry and where they intersect is the centre of mass

Question 27

How do tou find the centre of mass in an irregular object

Answer 27

If card is hung from a thread, the centre of mass is always centered, in line with the thread.Suspend the card, attach the Plum line. Using a pencil, draw a line along the plumb line.
Repeat the last step from a different side. Centre of mass is where the lines meet.

Question 28

Explain the motion of people on a slide

Answer 28

The people are accelerating at the top because of gravity and when they get closer to the bottom they deccelerate because of friction

Question 29

What is the independent variable

Answer 29

The variable you change

Question 30

What is the dependent variable

Answer 30

The variable you measure

Question 31

What is the control variable

Answer 31

The variable you keep the same

Question 32

What is repeatble

Answer 32

When the same person repeats the same test with the same method and equipment ane get similar results

Question 33

What is reproducable

Answer 33

Another person does an experiment again or a different method or equipment is used, they will get similar results

Question 34

What does reliable mean

Answer 34

Data that is reproducible and repeatable

Question 35

What does valid mean

Answer 35

Results which are repeatable and reproducible and answer the original question

Question 36

What is precise

Answer 36

Reaults where all the data is really close to the mean

Question 37

What is accurate

Answer 37

Results which are very close to the true value

Question 38

What is resolution

Answer 38

The smallest non zero reading that can be measured. E.g 1mm on a ruler

Question 39

How do you calculate the uncertainty

Answer 39

You do range divided by two
E,g 15.2-15=0.2/2=0.1 which is the uncertainty