Forces, Motion and speed Flashcards
(24 cards)
What is a variable that is changed in an experiment?
An independant variable
What is the variable that is measured in an experiment?
A dependant variable
The rate at which speed changes over time?
Acceleration
What are the 5 things that forces can make objects do?
- speed up
- slow down
- Change direction
- change shape
- turn
What is a force?
- A force can be a push or pull movement
- Forces can be contact or non-contact
- Forces can be balanced or unbalanced
- It can change objects in speed, shape and direction
What is the formula for speed?
Speed = Distance/Time
What are forces measured in?
Newtons
Name contact forces?
- Upthrust
- Friction
- Air-Resistance
What are examples of non-contact forces?
- Gravitational force
- Magnetic field
Define Upthrust
The upward force
Define gravity
The force that attracts an object to the centre of the Earth
What is friction?
It is a force that slows objects down, and created when one object rubs against another
What is air-resistance?
The opposite force to movement, and it is created by particles.
Explain why air-resistance increases when you move faster
There will be more particles
Which force pulls you down when skydiving
Gravity
Which force slows you down while skydiving
Air-resistance
Which force hits against the car when driving?
Air-resistance
Which direction does gravitational force apply?
Downwards
Suggest what would happen to the weight and mass of an astronaut on the moon
The weight would be different because when you are on the moon there is less gravity pulling you down, however the mass will stay the same as you will still contain the same amount of atoms in your body.
Why do dolphins have a streamlined shape
So that it can move through the water with the least possible water-resistance
What happens to the air-resistance when the parachute is opened?
Since the parachute has a big area there will be more particles hitting it so the air-resistance
will become greater, causing the person using it to slow down.
Explain the difference between mass and weight
Weight is the force that pulls you down.
Mass is the amount of atoms in the body
What is the force that keeps you afloat in water?
Upthrust
When are forces balanced?
Forces are balanced when they are equal in size but are opposite in direction. The forces cancel each other out
