Physics COPY 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.
Why do objects fall at the same speed?
Because even if they have different weights pulling them down, it takes inertia to move a bigger mass, which evens it out.
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 a moment and how do you work it out?
It is a turning effect of a force.
Moment (Nm) = force x perpendicular distance between the direction of the force and the pivot.(m)
What is the centre of gravity
It is the point through which the weight of a body acts.
How can you work out the centre of gravity of an irregular object?
Hang it and a plumb line from the same point. Make a mark, repeat. Look where the lines cross.
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.
What are the different parts of the universe called?
The universe is everything in existence.
A galaxy is a collection of stars.
A solar system is a group of planets orbiting around the sun.
What causes orbits?
Objects have forwards motion, but also has the perpendicular force of gravity keeping it close to the planet/sun.
What is a comet and how does it orbit?
They are lumps of icy rock. They have elliptical orbits, and travel much faster when nearer to the sun because the increased pull of gravity makes it speed up.