MC
1. A or C - most probable A, cos the velocity does keep changing? doesnt it? the velocity of the ball at the top its motion zero - is also correct. but that means the velocity is changing anyway = A
2.D - atmosperhic drag, gravity is too strong orbit is stupid how was it initially in orbit? sun's solar wind do not affect low earth orbits.
3.A, mass of space probe is importnat, radius is important, and universal gravitational is a constant and does is needed. tricky, relates to the escape velocity equation,
4.Either C or D, i thinks its D, anyhow if you reduce its orbital speed, the probe will not maintains its orbital velocity and fill into a lower orbit or collide with the planet. Damn i put D its C i think.
5.B, 45 degress is optimal angle for longest range.
6.D, orientation of the wire has absolutely no effect at all on the current produced. the earths magnetics field is small and doesnt effect this, it is also relatively constant.
7.TRicky, um either A or D
8.D- transformers only work with AC current, switch is closed means current is flowing, so not A, B and C are not sine graphs.
9. B- easy, cos eddy current only affect metals, plastic no eddy current falls first, copper with slit, has smaller edy currents than the other copper solid.
10.B- easy, the first one no insulations, energy is lost as heat, C, the wire is wrapped arounf an insulator so nothing will happen and it will heat up. D, is ridiculour same as C. B the insulationing materials creates smaller eddy currents that reduce heat, therefore less energy is llost as heat.
11.B - should be obvious
12.not sure either A or B, methinks A, cos Einstein didnt explain black-body radiation, Planck did with his packets. einstein explained photoelectric effect and relativity.
13.A or C, methinks A -jsut cos a nerd told me
14.work it out = B
15. D as electrns and holes have opposite charges and the magnetic fields sends them across in different directions (though they could attract each other)? whoa nice question.