2i) Show that k = 2 ii) Show that CM is (0.625, 0) iii) angle was 72.6 degrees
3i) Show that the diff. equation holds. ii) equilibrium position is at x = 4 iii) amplitude = 0.2m, period = 2pi/sqrt(10) iv) velocity = 0.384ms^-1 downward
4i) cos(alpha) = 1/3 ii) Show speed is sqrt(ag/3) iii) k = 2/3 iv) -(8/3)mg
Conservation of energy to get the speed of P just before collision, then conservation of momentum to get the speed of the combined mass just after the collision (in terms of k). Then conservation of energy again, because you know its speed when it gets to A. Quite an involved question!
What are people thinking for grade boundaries? It was weird because it was really easy up to the last 2 parts of the last q. So I'm thinking maybe slightly lower than usual maybe 66 or 67 for A* and 71 for full?
2i) Show that k = 2 ii) Show that CM is (0.625, 0) iii) angle was 72.6 degrees
3i) Show that the diff. equation holds ii) amplitude = 0.2m, period = 2pi/sqrt(10) iii) velocity = 0.384ms^-1 downward
4i) cos(alpha) = 1/3 ii) Show speed is sqrt(ag/3) iii) k = 2/3 iv) -(8/3)mg
Please add in/correct as necessary ^^
Yeah, you get -14/3 if you don't take into account that the mass has changed after the collision
Conservation of energy to get the speed of P just before collision, then conservation of momentum to get the speed of the combined mass just after the collision (in terms of k). Then conservation of energy again, because you know its speed when it gets to A. Quite an involved question!
Do u remember the equation for k? Or just the steps of that cuz I got 16/9 using the same method, idk if it's a calculation mistake or not
What are people thinking for grade boundaries? It was weird because it was really easy up to the last 2 parts of the last q. So I'm thinking maybe slightly lower than usual maybe 66 or 67 for A* and 71 for full?
Frankly, loads of ppl got those two questions right
I got 16/9 for k using the conservation of energy, wtf
Some energy would've been lost in the collision. I used conservation of energy to fine the speeds of P and P and Q at the bottom and conservation of momentum to find the mass.
2i) Show that k = 2 ii) Show that CM is (0.625, 0) iii) angle was 72.6 degrees
3i) Show that the diff. equation holds ii) amplitude = 0.2m, period = 2pi/sqrt(10) iii) velocity = 0.384ms^-1 downward
4i) cos(alpha) = 1/3 ii) Show speed is sqrt(ag/3) iii) k = 2/3 iv) -(8/3)mg
Please add in/correct as necessary ^^
Yeah, you get -14/3 if you don't take into account that the mass has changed after the collision
Conservation of energy to get the speed of P just before collision, then conservation of momentum to get the speed of the combined mass just after the collision (in terms of k). Then conservation of energy again, because you know its speed when it gets to A. Quite an involved question!
Okay thank you. I couldn't see how to find velocity of p just before the collision .... Did they give us the angle at which p and q collided?
2i) Show that k = 2 ii) Show that CM is (0.625, 0) iii) angle was 72.6 degrees
3i) Show that the diff. equation holds ii) amplitude = 0.2m, period = 2pi/sqrt(10) iii) velocity = 0.384ms^-1 downward
4i) cos(alpha) = 1/3 ii) Show speed is sqrt(ag/3) iii) k = 2/3 iv) -(8/3)mg
Please add in/correct as necessary ^^
Yeah, you get -14/3 if you don't take into account that the mass has changed after the collision
Conservation of energy to get the speed of P just before collision, then conservation of momentum to get the speed of the combined mass just after the collision (in terms of k). Then conservation of energy again, because you know its speed when it gets to A. Quite an involved question!
you know you're in for a good mark when all your answers are the same as strangebanana's
also I reckon this years grade boundaries might be reasonably high simply because I felt like this paper was unusually short for an M3 paper (4 marks for writing amplitude and period LOL and 7 marks for the part (i) show that in question 3), so there won't be enough people running out of time to keep the grade boundaries down. In terms of the difficulty of the questions hard to say whether it is any different from the average though.