physics mcq help needed! urgent!

[astarmathsandphysics]

mj 2004 q 9
vertically s=1/2at^2
1.25=1/2*10*t^2  so t^2 =0.25 so t=0.5
horizontally distance=speed*time
10=speed*0.5 so speed=20
25 A move the wave right a bit and see how P and Q have moved

[mz]

may/june 09 questions 15,19 and 29 please asap

[ruby92]

M/J 2009
10 13 20 33

[halosh92]

un 2005
Q3
Q4 plzzz someone help
3 speed is d/t=100/10=10m/s
1/2mv^2=1/2*80*10^2=4000J
4 error in 2.5=2% error in 40=0.25%
sum of errors=2.25%
40/2.5=16 +-2.25%=16+-0.36
I think they do this wroong

for Q4 i got the same answer as yours ..so the ms is wrong?

[Phosu]

12 The diagram shows the masses and velocities of two trolleys about to collide.
-->              --->
2 kg            4 kg
4 m s–1       1 m s–1

After the impact they move off together.
What is the total kinetic energy of the trolleys after the collision?
A1.3J B12J C18J D19J

[mz]

november 09/ 11 ---question number 15

[halosh92]

2009 june Q18
explain plz

[Phosu]

2009 june Q18
explain plz

this is wat i think

the formula for pressure is pa=hdg
since the pressure here is increasing, cuz heat is being applied to gas, ke increase, causing the height of the mercury to increase
A is rong since its not the correct formula
B is rong since it would give the height before the gas was heated
C is rong cuz it shows pressure decreasing, but we want the pressure to increase
D is the only correct option.

[[Spy]]

2009 june Q18
explain plz

since pressure is = row*g*h

and the height increase is h then the pressure increase should be simply row*g*h

BUT, if you think about it, the left coloumn of liquid goes down by H and the right side colomn of liquid goes up by H, and therefore its row*g*2h which is D

[halosh92]

since pressure is = row*g*h

and the height increase is h then the pressure increase should be simply row*g*h

BUT, if you think about it, the left coloumn of liquid goes down by H and the right side colomn of liquid goes up by H, and therefore its row*g*2h which is D

ahhh ure awesome thxxx

[[Spy]]

ahhh ure awesome thxxx

haha thanks
no problem

[halosh92]

june 2009 p1 cie
Q10
Q13
explain plz

[halosh92]

Q20 same paper

[ruby92]

O/N 2009
10 14 13 29
20 is maxima n*2?
21 why is it not B??

[halosh92]

O/N 2009
10 14 13 29
20 is maxima n*2?
21 why is it not B??

which variant 1 or 2?