Mechanics | Relativity Answers

If a 5-kg steel plate is attached to one end of a 0.1m x 0.3m x 1.2m wooden pole, what is the

length of the pole above the water? Use density of wood 0.50. Neglect buoyant force on steel.

the elastic constant of a helical spring is 9 N/m. a 1 kg body is attached from the spring and is made to move with simple harmonic motion. determine the period of vibration of the body and the acceleration when the body is 40 cm from its equilibrium position if the amplitude is 80 cm

The velocity of a particle which moves along

the s-axis is given by

V=2 - 4t + 58312

, Where t is in seconds and v is

in meters per second. Evaluate the position s,

velocity v, and acceleration a when t = 3 s. The

particle is at the position S, = 3 m when t=0.

A man runs around a circular track of 800 meters radius for 30 seconds, starting at a point directly to the right of the center and goes in a counterclockwise manner. He goes 5 meters per second for the first 15 seconds, runs 90 meters for the next 6 seconds and then 180 meters for the rest of the course. What was his average speed?

A particle of mass 10kg is placed on a rough plane inclined at angle of 30degree to the horizontal. What horizontal force is required to move up the plane

A car is being driven along a road at 25 m s-1 when the driver suddenly notices that there is a fallen tree blocking the road 65 m ahead. The driver immediately applies the brakes giving the car a constant acceleration of -5 m s-2.  How far in front of the tree does the car come to rest?

In travelling the 70 cm along a rifle barrel, a bullet uniformly accelerates from rest to a velocity of 210 m s-1. Find the acceleration involved and the time taken for which the bullet is in the barrel.

A car is being driven along a road at 25 m s-1 when the driver suddenly notices that there is a fallen tree blocking the road 65 m ahead. The driver immediately applies the brakes giving the car a constant acceleration of -5 m s-2.  How far in front of the tree does the car come to rest? Ans: 2.5 m before.

A person has a reasonable chance of surviving an automobile crash if the deceleration is no more than 30 g's.

a. Calculate the force on a 68-kg person accelerating at this rate.

b. What distance is traveled in meters if brought to rest at this rate from 95 km/h?

Suppose the mass of a fully-loaded module in which astronauts take off from the Moon is 20,000 kg. The thrust of its engines is 70,000 N. The acceleration due to gravity on the moon is 1.51 m/s².

Calculate the magnitude of acceleration in a vertical takeoff from the Moon.