Mark scheme for as many Qs as can remember:
Multiple Choice: (NOT IN ORDER)
1 - Force
2 - Graph of potential/kinetic energy going straight down from left to right
3 - extension question was 2 delta X.
4 - mgh/t
5 - mg sin theta
6 - 0.56 Joules (i think it was around that might be 0.58)
7 - work = force * displacement (2 vectors give scalar)
8 - maximum stress at maximum stress of graph
cant remember the other two
Section B:
NOT IN ORDER
Newton's third law question:
An object exerts and equal and opposite force of the same type and magnitude on an object that exerts a force on it. The two forces were a third law example becasue:
Same magnitude (300N)
Same type
opposite direction
on two different bodies
same time
Terminal velocity question:
about 2ms-1
spring constant question:
about 31.97 Nm-1 i think
Viscosity question:
increase in viscosity decreases velocity
increase in temperature decreases viscosity so velocity increases
elevator speed question:
0.8 ms-1
graph was a triangle up to 0.8ms-1 at 2 seconds, straight line until 5 ms-1, and then same triangle down (-0.8 ms-1)
broken hook question:
brittle because it breaks with no plastic deformation so it doesn't change shape and can be fitted back together...
SUVAT
Horizontal:
2.13 i think (1.88/088)
Vertical:
4.27 ms-1?
Magnitude and angle:
IF 4MS-1 AND 2MS-1 USED, AS GIVEN:
63.8 degrees and 4.47 ms-1
IF 2.13 and 4.3 used:
64 degrees and 4.8 ms-1
Define laminar and turbulent:
Laminar - Parallel flow lines, no sudden change in speed or direction, no mixing of layers etc.
Turbulent - Mixing of layers, sudden changes of speed and direction and eddy currents formed etc.
Diagram - straight lines up to obstruction then mixing of lines past it
Last question about how you can tell that the elevator was going up:
- extension decreasing
- so coils must be getting closer together/being compressed
less than 3Joules question:
I got 2.38 Joules i think
question about how filming it benefited:
Allowed them to see results more accurately, i.e. can be slowed down and paused to see, for example, exactly how long it takes to reach maximum height etc.
Also, eliminated human error and different people have different reaction times so more reliable.
Question about labelling particle:
cant remember if it was going up or down:
If down: Weight down, upthrust and drag (viscous) upwards
If up: Weight down, drag down, and upthrust upwards
Equation connecting this:
If up: Weight + drag = upthrust
If down: Weight = drag + upthrust
(Now pretty sure it was going down)
Explain why it accelerates then reaches steady speed question:
let's say it was going down:
weight is greater than upward forces initially
but then upthrust and drag increase to equal weight so constant speed because no resultant force
That's all I can remember but some of it is bound to be wrong!!! so sorry!