Classical Mechanics Answers

A spring with mass of 2 kg has natural length of 0.5 m. A force of 25.6 N is required to maintain, it stretched to a length of 0.70 m. If the string is stretching to a length of 0.70 m and then released with initial velocity 0, find the position of mass at anytime t.

A university graduate standing on the ground fires a rocket into the atmosphere at a velocity of 4000 m/s at an angle of 20 degrees to the vertical axis. Determine (g = 9.8 m/s2):

(a) The time of flight

(b) The maximum level

3. The position of a particle moving along the x-axis is given by x = 7t^2 + 2t^3, where x is in meters and t is in seconds. Determine the following, when t = 1.4 s:

(a) The position (2) (b) The velocity (2) (c) The acceleration (2)

A university graduate standing on the ground fires a rocket into the atmosphere at a velocity of 4000 m/s at an angle of 20o to the vertical axis. Determine (g = 9.8 m/s2):

(a) The time of flight (3) (b) The maximum level

b) Find the power delivered to an element at t = 3 ms if the current entering its positive terminal is i = 5cos60πt A and the voltage is

(i) v = 3i

(ii) v = 3di/dt         

an appliance cord is consist of two wires, about 2m long with individual wire which is about 3mm apart and carry a current of 8A DC. calculate the force exerted by the wires.

protons in a uniform magnetic field 0f .3 T follow a circular trajectory with 20 com radius. determine the speed of protons. ( q = 1.6 x 10^-19 and m = 1.673 x 10^-27 K )

Assuming that a kilogram rat and a hundred kilograms elephant fell on the cliff at the same time, which of the two will reach the ground first if air resistance and surface area are neglected? Explain.