Forces test Flashcards
what is the name of the equipment used to measure force
Newton Metre
What is the force between shoes and the ground?
Friction
What is a force
A push, pull or twist that acts between two objects
What can forces change?
Speed
Direction
Shape
of an object
When demonstrating forces, what does the length of arrow tell you?
The size of the force
In a diagram of forces, what does the bigger arrow mean?
The greater force
What is mass?
Mass is how much material an object has
What is weight?
The force due to gravity pulling on an object’s mass
What is the effect of mass on an object
The more mass an object has the more gravity pulls on it, making it weigh more
What are forces measured in
Newtons
What is mass measaured in
Kilograms
What is weight measured in and why?
newtons. Because weight is a force.
What is the equation for weight
weight = mass x gravity (field strength)
what is Earth’s gravitational field strength
10 newtons/kg
True or false weight stays the same but mass changes
False. Mass stays the same bit weight changes depending on gravitational field strength
Give an example of an unbalanced force
A game of tug of war where there are two people on one side and only one on the other.
Name the forces acting on a moving car
air resistance
friction
weight
drive
reaction
Name the forces acting on an aeroplane
life
drag
thrust
Name the forces acting on a boat
weight
thrust
drag
buoyancy
Name the forces acting on a skydiver
gravity
air resitance
What is terminal velocity
it is the fastest speed you can fall at
How is terminal velocity reached?
Terminal velocity is reached when an object’s weight is equal to its drag as it falls through the air
What is work done. What is the equation
work done is the energy transfered when a force acts over a distance.
Equation: work done = force x distance
What is work done measured in
joules
What is power
power is the rate at which energy is transfered OR the rate at which work is done over time
What is power measured in
Watts
What is a turning effect
turning effects are forces that cause an object to turn or rotate, these are called moments of forces or ‘moments’.
When do turning effects arise. Give an example
turning effects occur when a force acts along a lever arm at some distance from a pivot point. E.g. a mechanic turning a spanner.
What is the calculation for moments
moments = force x distance from pivot
What unit are moments measured in
Newton Meters
