Mechanics | Relativity Answers

Use 2 methods (uniform motion equations and the principle of conservation of energy) to check the accuracy of the statement at the beginning of the passage that a diver jumping from the high platform will hit the water at 30mph.

Moving walkways are often found in airports. One moving walkway carries passengers up an incline of 30°, A single passenger of mass 72 kg stands on the walkway. The speed of the walkway is 0.51ms−1. Show that the rate at which the walkway does work on the passenger is about 200W.

A 14-pound bowling ball feels a net force of -4.7 N as it slides down the lane. What is the acceleration of the bowling ball? (1 kg = 2.2 lbs)

A motorcycle travelling 24 m/s comes to rest in 8.7 s. What is the force of friction of the road against the bike tires if the bike weighs 8,200 N?

A particle has acceleration (a) while moving with uniform speed v in a circle of radius r. Start with a ∝ rⁿv^m. Derive the relationship between a, r and v using dimensional analysis. 

A particle of rest mass m0 is moving with speed v. Its classical kinetic energy is Kcl = 1 2m0v 2 . Let Krel be the relativistic expression for its kinetic energy. By expanding Krel/Kcl in powers of v 2/c2 , estimate the value of v 2/c2 for which Krel differs from Kcl by 10 percent. For this value of v 2/c2 , what is the kinetic energy in MeV of an electron and a proton? (Kleppner 13.3)

If a mass of 0.8 kg is constructed at one end of a 0.5m long fiber and rotates in a horizontal circle with an angle of 10 rads, then its angular momentum about the center of rotation, in SI units

If a mass of 0.8 kg is constructed at one end of a 0.5m long fiber and rotates in a horizontal circle with an angle of 10 rads, then its angular momentum about the center of rotation, in SI units

Give a critical explanation of Gaseous hypothesis of Kant regarding the origin of Earth and solar system.

A satellite going around Earth in an elliptic orbit has a speed of 10 km s−1 at the perigee which is at a distance of 227 km from the surface of the earth. Calculate the apogee distance and its speed at that point.