Mechanics | Relativity Answers

A particle makes a head-on-collision with an unknown particle at rest.The proton rebounds back with 4/9 of its initial kinetic energy.Find the ratio of mass of unknown particle to mass of proton assuming the collision to be elastic.

Particle [i]A[/i] of mass '[b]m[/b]' has initial velocity [b]v[/b]. After colliding with a particle [i]B[/i] of mass & '[b]2m[/b]' the particles have the following paths [i]B[/i] makes an angle [b]45[/b] degree while [i]A[/i] makes an angle [b]X[/b]. & First, & [i]A[/i] was moving straight. & Find [i][b]X[/b][/i].

Consider a ball of mass m1 moving with a velocity u1 collides elastically with a ball of mass m2 at rest.Show that the maximum energy transfer takes place when m1=m2.

A half inch garden hose can discharge five hundred gallons of water per hour under normal water pressure conditions.
What is the velocity of water leaving the garden hose under these conditions, in ft/min?

A ball is thrown upward from the ground with an initial speed of 18.2 m/s; at the same instant a ball is dropped from rest from a building 12 m high. After how long will the balls be at the same height?

A world class sprinter can reach top speed, 11.5m/s, in the first 15.0m of a race. What is the average deceleration of this sprinter and how long does it take her to reach that speed?

A body is dropped from a point 4.9m above a window 1.5m high. Find the time taken by the body to pass against the window.

A man standing under a black umbrella in hot day, why he does not feels hot????

A man walks 240m in 30s & then walk back 140m toward the starting point in the next 35s. What is the average speed and velocity?

For determining the area of a cube, why do we use cross product and not dot product?