Mechanics | Relativity Answers

A force is applied on a body mass 50 kg for 8 sec. After that force is removed, but the body continuous in motion for 5 sec and covers 80m displacement. Find the force applied.

A bus starting from rest moves with a uniform acceleration of 0.1 m/s for two minutes . what is the speed of the bus aqquired.

I was on the American River, Paradise Beach, in Sacramento, CA. The river was cold, the beach sand was hot. I cupped both my hands together and scooped up as much hot sand is I could, then lowered the sand into the cold river. Almost instantly, the sand touching my hands became much, much hotter, almost too hot to hold. What explains this? Did the cold water concentrate the heat from the sand - against my skin?

An object of irregular geometric shape is lowered into a beaker of water. Find the volume of the
shape and the error of measurement.

A drop of oil with a volume of 0.003 cubic mm has spread out over the surface of water in a
monomolecular layer and has covered 300 quadratic cm. Find the diameter of the molecules.

A long, straight, current-carrying wire runs from north to south.
a. A compass needle placed above the wire points with its north pole toward the east. In
what direction is the current flowing?
b. If a compass is put underneath the wire, in which direction will the needle point?

A car and a motorcycle start from rest at the same time on a straight track, but the motorcycle is 25.0 m behind the car. The car accelerates at a uniform rate of 3.70 m/s2, and the motorcycle at a uniform rate of 4.40 m/s2. How much time elapses before the motorcycle overtakes the car? How far will each have traveled during that time? How far ahead of the car will the motorcycle be 2.00 s later?What is the distance traveled of both car and the motorcycle within that time? (Both vehicles are still accelerating.)

A study or proposal was carried out about time travel. Someone in east asia said that it was impossible to go forwards or backwards in time. They brought up that they can't tell if photons can move faster than "c." I read that the closer you move to the speed of "c" the further you'll excel forward in time. My question is that if an object is moving at x m/sec and throws off a beam of light; wouldn't that beam of light be moving at c + the velocity of the oject?

Give one example each where the effect of force is increased and where the effect of force is decreased.

A particle of mass m rotating with angular velocity w (omega) around a fixed axis at distance r from it is observed from a frame of reference rotating around the same axis with angular velocity w1. Find centrifugal force acting on the particle observed from this frame of reference. A) mw^2*r B) mw1^2*r C) m(w+w1/2)^2*r D) mw*w1r