Physics

Question 1

Define electric field (E)

Answer 1

• A region in which a charged object experiences a force.
• Increasing voltage or decreasing plate separation will increase field strength.

Question 2

What are the factors that affect resistance

Answer 2

• Length: Increased distance=Increased resistance.
• Temperature: Increase temp=Increased. resistance & more collisions as particles vibrate faster.
• Material/conductivity.
• Thickness: increased thickness=decreased resistance & less collisions/more space.

Question 3

Terminal velocity: skydiver example

Answer 3

1) at the start: air resistance is small - accelerates down
2)Speed increases - air resistance increases
3) eventually air resistance = weight force (terminal velocity) - balanced forces & constant speed.
4) open parachute: air resistance increases - slows down
5) slowing down- air resistance decreases until balances with weight - lower terminal velocity

Question 4

Define pressure (Pa)

Answer 4

Pressure is a measure of force applied to a particular area.

Question 5

How is pressure increased?

Answer 5

Pressure is increased by increasing the force in the same area or reducing the area the force is applied to.

Question 6

Define charge

Answer 6

Charge is a unit of matter that expresses the extent to which it has more or fewer electrons than protons.
It is a physical property of matter that causes it to experience a force when placed in an electro magnetic field.

Question 7

What is a disadvantage of series circuits?

Answer 7

• Any openings disrupt current of whole circuit
• A short in one device will cause an increase in current through all devices.
• Total resistance decreases overall power.

Question 8

Define Charge insulation (friction)

Answer 8

• When different insulating objects are rubbed together, electrons can be transformed between surfaces.
• The two objects will have equal and opposite charges so the electrons gained due to these electrons being lost from the cloth.
• A charged object creates a force field around it. other charged objects will be attracted or repelled in the force field.

Question 9

Disadvantages of parallel circuits.

Answer 9

• Requires a lot of wires (more expensive)
• Uneven current distribution can cause overheating or overloading of individual.

Question 10

advantages of parallel circuits

Answer 10

• Every component gets equal full voltage
• Bulbs will be brighter
• If one loop disconnects, other remains powered.
• Total resistance increases overall power.

Question 11

Advantages of series circuits

Answer 11

• They don’t overheat easily
• They are less expensive

Question 12

Parallel circuit rules

Answer 12

• Current (A) (i): current adds up to supply (Ir=I1+I2)
• Voltage (v): Same voltage across all components (Vt= V1 = V2=…)

Question 13

Series circuit rules

Answer 13

• Current (I) (A): Same current through all components.
• Voltage (v): Adds up to supply
• Resistance (R) (Ohms): Combine to give more resistance.

Question 14

Work

Answer 14

The transformation of energy

Question 15

Work done

Answer 15

The amount of energy transformed when a force causes an object to move a distance in the direction of the force.

Question 16

Define power

Answer 16

• Work done over time, Watts (W)
• Rate in which energy transformed

Question 17

Define Voltage (v)

Answer 17

The current of energy in one coulomb of charge.

Question 18

Define ‘Displacement’

Answer 18

The change in position of an object or the shortest distance between the initial and final position of an object.

Question 19

Scalar quantity

Answer 19

Has only a value (Magnitude)

Question 20

Define ‘Distance’

Answer 20

The total length covered by an object.

Question 21

Define ‘Velocity’

Answer 21

The rate of change of displacement.

Question 22

Define ‘Speed’

Answer 22

Rate of change of distance

Question 23

Define force (N)

Answer 23

• A push or pull
• Have a magnitude and direction
• Vector

Question 24

Net force

Answer 24

The resultant force when multiple forces ineract.

Question 25

Newton's Laws of Motion

Answer 25

1) An object cannot start, stop, or change direction all by itself. 2) The force applied on an object is equal to the product of its mass and acceleration. 3) For every action, there is an equal and opposite reaction.

Question 26

Vector Quantity

Answer 26

Has a value (magnitude) and direction

Question 27

Friction and Drag

Answer 27

-Friction is a contact force that acts to oppose sliding motion between surfaces -Drag is friction that occurs in liquid or gas. -When friction occurs, kinetic energy from movement is changed into heat energy.

Question 28

Unbalanced Force

Answer 28

- Net force - Acceleration in direction of net force - Change in motion/speed

Question 29

Balanced Force

Answer 29

- No net force - No acceleration - No change in motion/speed - constant speed

Question 30

Difference between mass and weight

Answer 30

Mass is the amount of matter an object is made up of. This does not change. whereas, weight is the downwards force due to gravity that an object experiences due to its mass. weight can change depending on location and gravity.

Question 31

What is Air resistance

Answer 31

- Acts in an upwards direction -The result of collisions of the objects leading surface with air molecules. -The more air molecules an object collides with, the greater the air resistance force. - dependent on speed & surface area

Question 32

Terminal Velocity

Answer 32

- Travelling at a constant speed - Force of gravity accelerating the skydiver towards earth are marched exactly by the force of friction the air particles pushing against the skydiver. - If person points body down or wears more aerodynamic suit there is less surface area to act against the air which reduces friction. Therefore, terminal velocity will be faster.