Mechanics | Relativity Answers

an electric train is moving in the velocity of 120km/hr.how much distance it will move in 30sec,

a bomb is dropped from an airplane moving horizontally with a speed of 200km/h. if the air resistance is negligible, the bomb will reach the ground in 5sec when altitude of the plane is approximately?

a student wanted to make a pendulum whose period would be one second. He used a string of length "L" and found that the period was 1/2 sec. To get the desired period. He should use a string whose length equal?

Two point charges are fixed in place, as in the figure below. The positive charge is +2q and has
twice the magnitude of the negative charge, which is -q. On the line that passes through the charges, three spots are identified, P1, P2, and P3. At which of these spots could the potential be equal to zero? (a) P2 and P3 (b) P1 and P3 (c) P1 and P2 ……

What chnges do u notice when
1)steel ball
2)cue ball
3)bouncy ball
4)tennis ball
are falling from a same distance on a hard metal plate.which one will ascend the max height?

These questions consist of two statements each, printed as Assertion and Reason. While answering these Questions you are required to choose any one of the following four responses.

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are False.
Assertion :- A body may gain kinetic energy and potential energy simultaneously.
Reason :- Conservation of mechanical energy may not be valid every time.
(1) A (2) B (3) C (4) D

a particle covers 60 km at a uniform speed at 60 km/h. what should be it's speed for the next 120 km if the average speed for the entire journey is 60 km/h.

A net torque of 36 N.m acts on a wheel rotating about a fixed axis for 6 s. During this time the angular speed of the wheel increases from 0 to 12 rad/s. The applied force is then removed, and the wheel comes to rest in 75 s.
a. What is the moment of inertia of the wheel?
b. What is the magnitude of the frictional torque?
c. How many revolutions does the wheel make?

1. Two carts, one twice the mass of the other, experience the same force for the same time. What is their difference in momentum? What is their difference in kinetic energy?

A string of length L and mass M is lying on a horizontal table. A force F is applied at one of its ends. Tension in the string at a distance x from the end at which force applied is

(a) zero

(b) F

(c) F(L−x)/L

(d) F(L−x)/M