Ok a handful of questions which I am unsure of.
1. A satellite is moving in a circular orbit around Earth. A
piece of it becomes detached. Assuming that air resistance can be
neglected, this piece will
A move directly away from Earth
B fall directly towards the Earth
C continue to move in a circular path
D continue to move along a tangent to the orbit.
2. When a gun is fired from a stationary aeroplane, the bullet
has a speed v and a kinetic energy K. The gun is again fired,
straight ahead when the plane is flying at a speed equal to v. The
kinetic energy of the second bullet is
A K B
(2K)^0.5 C 2K D
4K
I chose K, but I am unsure about it. (l was thinking abt sth
along the lines of internal energy althou this is NOT a question
related to I.E, but i think being on a plane does not affect K.E of
the bullet? well, no idea).
3 R is the electrical resistance measured btw the ends of a
cylindrical conductor of radius r. If a hole of r/2 is drilled
along the axis of the cylinder from one end to the other, the new
resistance will be
R/4 R/2
4R/3 3R
I found that the resistance of the SMALLER and drilled wire is
4x MORE than the original cylinder. So original cylinder is R,
smaller and drilled one is 4R. the remaining resistance of the
leftover cylinder should be R<ans<4R. So the ans is either
4R/3 or 3R. But I dont know how to proceed further from here.
4. Which of the following statements is true for the motion of a
spherical ball falling from rest thru a homogenous liquid? (simple
question but I am uncertain about it, lol)
velocity decreases as distance fallen increase
velocity remains constant
acceleration is constant
acceleration decreases as distance fallen increases.
At first I chose the last option, but what are the EFFECTS of
being in a homogenous liquid? (Air resistance constant? if thats
the case, should i choose the 3rd option instead?)