Physics MOCK Flashcards
What is the link between speed, distance, and time?
distance = speed x time.
How do you work out acceleration?
The change in velocity / time taken.
What does a flat, curved, and diagonal line mean on a distance time graph?
Stopped, accelerating or decelerating, and steady speed.
What does a flat, curved, and diagonal line mean on a velocity time graph?
Steady speed, increasing acceleration, and constant acceleration.
How do you work out distance on a velocity time graph?
The area.
What is gravity and what is weight?
Gravity is the force of attraction between all masses. Weight is the force with which gravity pulls any given object.
What are the units for weight and gravity.
Gravity is in N/Kg (how much force attracts a mass of 1Kg)
Weight is in N
What is the link between mass, weight, and gravity?
Weight = mass x gravity.
What happens to friction as speed increases?
It increases.
How could you investigate the motion of a toy car on a ramp?
Use light gates set apart equal distances and record with data-logging software.
What causes terminal velocity? What affects it?
As a falling object accelerates, the resistance increases. When the resistance force becomes equal to the weight pulling the object, the object will not be able to go any faster.
The weight, surface area, and aerodynamics.
What happens when there are balanced and resultant forces?
A balanced force will either mean constant speed or no motion.
A resultant force will mean acceleration.
What is the link between force, mass, and acceleration?
Force = mass x acceleration
What is the difference between a scalar and a vector?
A scalar only has a size and a vector has a size and direction.
What 2 factors affect stopping distance and what affects these?
Thinking distance: speed, and dopiness.
Braking distance: mass, speed, conditions.
What is Hooke’s law?
It is that the extension of a wire or spring is directly proportional to the force pulling it.
What happens if you stretch a wire or spring far enough?
It will reach it’s limit to proportionality, and then it’s elastic limit so it won’t return to it’s original shape.
How should a plug be wired?
- The neutral (blue) wire is on the left,
- The green/yellow earth wire is in the middle,
- The live brown wire is on the right with the fuse.
What is double insulation?
When an object is plastic coated with no metal parts showing. This means that no earth wire is needed.
What are some safety precautions for plugs?
- Check it isn’t damaged.
- Check there’s no water.
- Turn the socket on and off
- Don’t have too many plugs from one socket.
How does an earth wire work?
It stops you from getting a shock if there is a short circuit or accident, and an appliance becomes live. It provides a low resistance path for the electricity to flow to earth instead of through you.
What are the differences between fuses, circuit breakers, and RCCBs?
- Fuses have a wire inside that melts if there is too much current.
- Circuit breakers detect a surge in current and switch off, but can be reset with a press of a button.
- RCCBs detect a difference in current between the live and the neutral wires and switch off.
What is a side effect of an electric current?
The wire gets hot.
How do you work out electrical power?
current x voltage (in watts)