Force and Motion

Question 1

Acceleration:

Answer 1

is the rate of change of speed

Question 2

Displacement:

Answer 2

is a vector quantity and describes the overall change in position of an object from its original position

Question 3

Inertia:

Answer 3

Is the object’s resistance to motion

Question 4

Inertia devices:

Answer 4

Devices used as safety measures against inertia e.g. seat belts, airbags and head rests

Question 5

Instantaneous speed:

Answer 5

Is the speed of an an object at any particular time

Question 6

Scalar:

Answer 6

Is a quantity which has magnitude only

Question 7

Vector:

Answer 7

Is a quantity which has magnitude and direction

Question 8

Weight force:

Answer 8

Force on any object due to gravity

Question 9

How do you calculate:

Average velocity=

Answer 9

displacement/ time 
where: 
Velocity is in metres/ per second (m/s or m/s-1) 
Displacement in metres
Time in seconds

Question 10

How do you calculate:

Acceleration=

Answer 10

final velocity- initial velocity/ time taken 
where:
Final velocity (m/s) 
Initial velocity (m/s)
Time (s) 
Acceleration (m/s/s or m/s2)

Question 11

For an object to accelerate a force is required. For the same object:

Answer 11

o A bigger force causes a faster acceleration than a smaller force
o A smaller mass will accelerate quickly than a larger mass

Question 12

Conversion:

m/s -> km/h

Answer 12

X 3.6

Question 13

Conversion:

km/h -> m/s

Answer 13

Divide 3.6

Question 14

What are the three types of motion graphs?

Answer 14

• Displacement time graph
• Velocity- time graph
• Acceleration- time graph

Question 15

Displacement- time graphs:

The slope gives______

Answer 15

object’s average speed/ velocity

Question 16

Velocity- time graphs:

The slope gives_____

Answer 16

the rate of acceleration

Question 17

What does the area under a velocity- time graph tell?

Answer 17

The distance travelled by an an object up to that line.

Question 18

Ticker timer:

Answer 18

A device that measures speed

Question 19

How many times does a ticker time vibrate per second?

Answer 19

50

Question 20

What is the time between each dot in a ticker time?

Answer 20

0.02 seconds

Question 21

Ticker timer:

1) Constant velocity
2) Acceleration
3) Deceleration:

Answer 21

1) dots are evenly spread apart
2) dots become increasingly apart
3) dots become increasingly closer together

Question 22

Force:

Answer 22

Is a push, pull or twist

Question 23

How can force change to motion of an object?

Answer 23

o Accelerating objects
o Decelerating objects
o Changing the direction of objects
o Changing the shape of objects

Question 24

Contact forces:

Answer 24

When there is direct contact between force and object

Question 25

Friction:

Answer 25

Force acting between two rubbing surfaces

Question 26

Air resistance/ drag friction

Answer 26

When air (or liquid) moves across an object

Question 27

Tension:

Answer 27

Force in a straight rope as it pull on an object

Question 28

Surface tension:

Answer 28

Force between water particles to form a skin/ film on the surface of a liquid

Question 29

Buoyancy:

Answer 29

Water force acting upwards to keep objects afloat

Question 30

Lift:

Answer 30

Upward force covered by air moving over an airfoil e.g. wing of a plane

Question 31

Thrust:

Answer 31

force caused by gases/ liquids being pushed out from a propeller or engine

Question 32

Non contact force:

Answer 32

Occurs when an object is within a force field

Question 33

Weight:

Answer 33

gravity pulls object downwards towards the centre of the planet

Question 34

Electrostatic:

Answer 34

force of charged object, same charges repel each other, whilst opposite attract

Question 35

Magnetism:

Answer 35

force of magnets where same charges repel whilst opposite attract

Question 36

Force diagram:

Answer 36

represent the forces acting on an object - Forces are drawn as line with arrowheads o Arrow heads represents direction - Length of arrow represents size

Question 37

Vector diagram:

Answer 37

allows us to sum the forces acting on an object (net force) and allows us to resolve if it is a balance or an unbalanced force

Question 38

Newton's first law of motion:

Answer 38

An object will remain at rest or continue moving at a constant velocity in a straight path unless acted upon by a net unbalanced force The heavier the object the more inertia it has The faster the object the more inertia it has

Question 39

Newton's second law of motion:

Answer 39

- The acceleration of an object is related to the size of the force acting on the object and the mass of the object - F=ma Where: F= force (N) m= mass (kg) a= acceleration (m/s2)

Question 40

Newton's third law of motion:

Answer 40

- For every action force , there is an equal and opposite reaction force - When an object applies a force to another object, the second object applies an equal and opposite force to the first object.

Question 41

Nuclear potential energy:

Answer 41

Stored in nuclei of atoms and when nuclei split or combined energy is released into other forms

Question 42

Law of conservation of energy:

Answer 42

Energy cannot be destroyed or created, only transformed or transferred

Question 43

KE=

Answer 43

``` 1/2 mv^2 Where; m= mass (kg) KE= kinetic energy (J) v= velocity (m/s) ```

Question 44

Kinetic energy:

Answer 44

Energy of motion NOTE: - the faster the object the more KE it has - the heavier the object the more KE it has

Question 45

Gravitational potential energy:

Answer 45

``` Stored energy as object is lifted. Hence when an object is released GPE will be converted into KE causing it to accelerate to the ground. GPE= mgh m= mass (kg) g= gravity (9.8m/s^2) h= height (m) ```

Question 46

Elastic potential energy:

Answer 46

Energy in objects which are stretched or compressed e.g. rubber bands, balls and spring. EPE is converted into KE

Question 47

Chemical potential energy:

Answer 47

Energy stood within chemicals. After a chemical reaction takes place, energy is converted into other forms e.g. kinetic, light, heat, electric

Question 48

Work:

Answer 48

``` Occurs when a force is applied to an object. With the amount of work done related to the force that has been applied and the distance the object has travelled. W= Fd where: W= work(Nm) F= force (N) d= distance (m) ```