Paper 2 - Forces and Motion Flashcards
1
Q
What is the equation for momentum?
A
p=mv
2
Q
Use the idea of momentum to explain safety features
A
- Change in momentum is the same with or without an airbag.
- Airbags and crumple zones in cars are used to increase the period of time that the collision takes to reduce the force of the impact
- Reduces rate of change of momentum
3
Q
Equation for force in terms of momentum
A
force=change in momentum / time taken
F=(mv-mu) / t
4
Q
What is Newton’s third law?
A
For every action (force) in nature, there is an equal and opposite reaction
5
Q
What is the equation for the moment of a force?
A
moment=force x perpendicular distance from the pivot point
M=Fd
6
Q
How does the weight of a body act?
A
The weight of a body acts through it’s centre of gravity
7
Q
What is the principle of conservation of momentum?
A
total momentum before collision = total momentum after collision
as long as there are no external forces acting
8
Q
How is an oscilloscope used to measure the time period of a wave?
A
- Freezing the screen
- To count number of squares in a full cycle
- Then multiply number of squares for full cycle by time base
