Section 1 Flashcards
If something has a smaller mass will it accelerate more?
Yes.
If you push something what force will the object push back at?
The same force.
Vectors?
Have size and direction.
Scalars?
Have size.
What is the resultant force?
When there is multiple forces acting on an object it is the overall force acting on the object.
Examples of vector quantities?
Force, velocity, displacement, acceleration, momentum.
Examples of scalar quantities?
Mass, temperature, time, length.
What is the resultant force of 220N north, 180N south and 90N south?
50N south.
Force =
Mass x acceleration.
Momentum =
Mass x velocity
Momentum before =
Momentum after.
Moment before =
moment 1 + moment 2
Moment after =
mass x velocity. Add two masses of objects together and they will equal the moment before, so just work out v.
What happens when a force acts on an object?
It causes it to change in momentum.
What does a larger force mean in terms of momentum?
A faster change in momentum, so a greater acceleration.
Force acting =
Change in momentum / time taken for change to happen.
How are cars designed for a crash?
To slow people down over a longer time.
Why do you wanted a longer time for a crash?
The longer it takes for a change in momentum, the smaller the force.
What do crumple zones do?
Increase the time taken for a car to stop.
How do seatbelt help?
They stretch slightly, increasing the time taken for the wearer to stop. This reduces the force acting on the chest.
How do air bags help?
They slow you down more gradually.
If an object is balanced then:
Total anticlockwise moments = total clockwise moments.
What happens if the total moments are not equal?
There will be a resultant moment.
