I got the angle of 30 too but i struggles with the first parts of the question, i think my equations were: 4*9.8-T=4a and 4*9.8+T=8a and then got a as 12. something

Overall I didn't like this exam especially the beginning of section A and the end of section B

i think mine were t=8a and -t+4g=4a

Same here

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Reply 64

Synmatic

Original post by Connorbwfc

Yes and initially t=0, so it is (2, 6) I think.

ah you're right dammit

Reply 65

Connorbwfc

Original post by Synmatic

ah you're right dammit

Did it ask for the initial velocity?

If so I think I am correct, but I'm not too sure now haha.

Reply 66

Synmatic

Original post by Connorbwfc

Did it ask for the initial velocity?

If so I think I am correct, but I'm not too sure now haha.

They should've specified initial velocity instead of 'u'

Reply 67

akpai22

You are correct u is (2 6)

Reply 68

Connorbwfc

Do people agree with these similarities and differences?

For A and B
Same: Constant acceleration of 10 for first 5 seconds.
Different: for 5-8 seconds A=accelerating, B=constant speed.

For B and C
Same: Both have a constant speed for 5-8 seconds. Both accelerating from 0-5 seconds.
Different: Different constant speed for 5-8 seconds -25 vs 50.

(edited 7 years ago)

Reply 69

akpai22

For the second to last questio of 7, i worked out the angles to workou t sinalpha and beta so i ended up getting an acceleration of -5×10^-4 instead of 0. Will i lose many marks??

Reply 70

zabveniye

Original post by prepdream

For the pigeon question, I set like 4=ut+1/2at^2, tried to solve it and said that there is no real root for the equation so it cant reach the pigeon? How do you guys solve this one?

I solved it by finding the maximum vertical displacement of the stone, i.e. where vertical velocity = 0. This was under 4m, so the stone could not have hit the pigeon. Your method sounds fine too, though :smile:

Reply 71

prepdream

How many marks is question 4 if anyone can remember? :smile:

Bloody forgot to put t=0 for u oh well

Reply 72

lukewtfwt

did anybody else forget to divide the 7500N but 9.8 to find the mass in the 7th question part ii.

Reply 73

lukewtfwt

Original post by prepdream

How many marks is question 4 if anyone can remember? :smile:

Bloody forgot to put t=0 for u oh well

the full question was 8 marks

Reply 74

zabveniye

Original post by Connorbwfc

Do people agree with these similarities and differences?

For A and B
Same: Constant acceleration of 5 for first 5 seconds.
Different: for 5-8 seconds A=accelerating, B=constant speed.

For B and C
Same: Both have a constant speed for 5-8 seconds. Both accelerating from 0-5 seconds.
Different: Different constant speed for 5-8 seconds -25 vs 50.

I answered exactly the same as you for B and C!

My answer for A and B was different, though, but I'm fairly sure I got that one wrong. Something about not taking mass into account for similarity (which on hindsight was probably completely irrelevant :closedeyes:

) and for the difference I put that initial acceleration for A was 5 whereas it was 10 for B

(edited 7 years ago)

Reply 75

♥Samantha♥

I can't believe I messed up the last question so bad when working out acceleration. I forgot that alpha and beta change and used my values of sin alpha and sin beta from an earlier part. Would I get any marks?

Reply 76

Connorbwfc

Original post by zabveniye

I answered exactly the same as you for B and C!My answer for A and B was different, though, but I'm fairly sure I got that one wrong. Something about not taking mass into account for similarity (which on hindsight was probably completely irrelevant :closedeyes:

) and for the difference I put that initial acceleration for A was 5 whereas it was 10 for B

I put that d=5T^2 for the first five seconds for both. In my original post it was meant to say 10 instead of 5 btw in the similarities for A and B.