Mock paper 2 questions Flashcards
1
Q
Why bumper cars stop after the crash?
A
- initially both have same momentum but in different directions
- total momentum = 0
- momentum is conserved
- momentum after collision = 0
2
Q
Explain why the coil rotates in when there is a current in the coil?
A
- current in wire has magnetic field
- current in opposite directions of each side of the coil
- forces act in opposite directions
- split ring commutator reverses the current
3
Q
What properties of springs would make the mattress soft?
A
- spring compressed high amount
- spring with lower spring constant
4
Q
How do forces change for plane to land?
A
- lift decreases so resultant force down
- thrust decreases air resistance increases
5
Q
Explain why violet light is refracted the most as it enters the water?
A
- violet has shortest wavelength
- travels slowest in water
- undergoes greatest change in speed
6
Q
What is inertia?
A
difficulty of changing an object’s velocity
7
Q
Why is egg less likely to break when dropped onto foam?
A
- impact is less
- foam increases time taken to stop
- decreases deceleration
