Mechanics | Relativity Answers

a car is moving at as speed of 15m/s.what is the time taken by it to cover the distance of 1.2km ?

hailstones falling vertically with a speed of 10m/s hit the wind screen(wind screen makes an angle 30 degree with the horizontal) of a moving car and rebound elastically. find the velocity of the car if the driver finds the hailstones rebound vertically after striking

an aeroplane is flying vertically upwards with a uniform speed of 500m/s. when it is at a height of 1000m above the ground a shot is fired at it with a speed of 700m/s from a point directly below it. what should be the uniform acceleration of the aeroplane now so that it may escape from being hit

If you attach one end of a spring to the ceiling, so it hangs vertically, and pull it down towards the floor on the other end. When you then sum all the forces, should you count gravity force as one of them? Could you draw all the forces working on the spring?

We all believe that Einstein's theory of relativity is correct and it is proved as well, but how an object shrink to nothing and it's mass becomes infinite if it is moving at speed of light?How an object can have infinite mass and shrink to nothing at same time?

after rolling halfway down an incline, a marbles kinetic energy is?

A car moves at constant 60km for 1km and 40km/hr next 1km what is the average speed of car

A ball thrown horizontally from a point 100 m above the ground with a speed of 20m/s. Find (a) the time it takes to reach the ground, (b) the horizontal distance it travels before reaching the ground, (c) the velocity (direction and magnitude) with which it strikes the ground.

men are running along a road at 15km/hr behind one another at equal intervals of 20m. cyclists are riding in the same direction at equal intervals of 30m at what speed in km/hr an observer travelling along the road in opposite direction so that whenever he meets a runner he also meets a cyclist

For hydrogen iodide, 1 H^127 I, force constant is 314 N m-1. Calculate the
fundamental frequency in cm^-1 unit for
i) 1H127I
ii) 2H127I
Hint: Assume that force constant does not change with isotopic substitution.