I think I got 128J or something less than 130J. I struggled with that question because originally I used 1/2 F deltax. But since I couldn't work it out, I checked the graph for Force applied for the compression of 6 cm and then I used that force in the work done equation (W= fs) with s = 6.
Some answers I remember, so if any of these could be confirmed correct, that would be a relief:
vector diagram: 13.4N, 46-47 degrees.
Projectile: 98m
Radius of raindrop: 2.4 x 10^-4m
Max velocity pogo stick: 2.5m/s
The radius of drop is correct the projectile distance is correct, i got 40.9 degrees and 18n resultant but i made a mistake on that, also the pogo stick is an ecf but 2.5m/s seems to be the correct answer
I said that too. I assumed it could not be change in GPE, obviously because one was steel and one was plastic so they must have different change in GPE's??
Yes me too, all the other options involved mass and the mass of the two must be different so I chose same v
I wrote about parallax and varying paint levels too, then about temperature again, I thought maybe saying hotter paint => shorter time would be worth a mark or something
I said that its hard to know when to start timing as there's nothing to block up the hole at the bottom of the cup so the liquid just flows out so distorts the final time recorded
Then also said for viscous liquids it'll stick to the sides and not all will pass through the cup so difficult to know when to stop timing and accept that its stuck on the walls of the cup and won't flow out.
I have done it in a weird way. Basically it said that the spring was compressed by 3cm in the pogo stick, so I used the graphs to get the value of force for 3 cm and than I got the value for force when the extension was 9 cm ( it specified that he has extended it by further 6 cm) I have subtracted the force for 3 cm away from the value I have read off the graph for 9 cm and multiplied it by 0.06 ( W=F * (delta) s ) I got 129J. I think that the mark scheme will have a range of values.
Answers so far: The issue with the paint timer: It's hard to know when to start timing as there's nothing to block up the hole at the bottom of the cup so the liquid just flows out so distorts the final time recorded.
Then also said for viscous liquids it'll stick to the sides and not all will pass through the cup so difficult to know when to stop timing and accept that its stuck on the walls of the cup and won't flow out.
vector diagram: 13.4N, 46-47 degrees. (I think there will be a range on the mark scheme maybe up to 50 degrees)
Projectile: 98m (around this)
Radius of raindrop: 2.4 x 10^-4m
Max velocity pogo stick: 2.5m/s
Energy transfers on the pogo stick: Elastic strain energy -> Ke+GPE
Yeah force, kinetic energy and the other one (can't remember) are all dependent on mass, which is different for each ball, velocity is the only one that isn't
velocity is constant and its easy to proof. vacuum, so no air resistance
all GPE goes to KE
mgh = 1/2mv^2
cancel masses
gh = 1/2v^2
v = root(2gh)
since, they were dropped from the same height, velocity will be the same in each case, irrespective of mass.