Mechanics | Relativity Answers

One of the tallest buildings in the world has a height of 1671 feet. Assume that this height was measured on a winter day when the temperature was 16°C. You could use the building as a sort of giant thermometer on a hot summer day by carefully measuring its height. Suppose you do this and discover that the building is 0.581 foot taller than its official height. What is the temperature, assuming that the building is in thermal equilibrium with the air and that its entire frame is made of copper?

The only force acting on a 2.8 kg canister that is moving in an xy plane has a magnitude of 5.8 N. The canister initially has a velocity of 4.4 m/s in the positive x direction, and some time later has a velocity of 6.7 m/s in the positive y direction. How much work is done on the canister by the 5.8 N force during this time?

How much work is done by pulling up on a suitcase at 40° elevation with a force of 5.00lb while moving it horizontally 1320.ft?

An object is in equilibrium if all the forces on it balance. The figure below shows a beam weighing 124 N that is supported in equilibrium by a 100-N pull and a force  at the floor. The third force on the bean is the 124-N weight that acts vertically downward.

An object is in equilibrium if all the forces on it balance. The figure below shows a beam weighing 124 N that is supported in equilibrium by a 100-N pull and a force at the floor. The third force on the bean is the 124-N weight that acts vertically downward.

What is the resistance of a 25.0-m-long piece of 12-gauge copper wire having a 2.053-mm diameter?

A body of mass 0.2kg is executing shmwith an amplitude of 2pcm. The maximum force which acts upon it is 0.064N. Calculate it's maximum velocity and period of oscillation.

Chris jumps off a bridge with a bungee cord (a heavy stretchable cord) tied around his ankle, (Figure 1). He falls for 15 m before the bungee cord begins to stretch. Chris's mass is 80 kg and we assume the cord obeys Hooke's law, F=−kx, with 54 N/m.

b) What is your acceleration at the bottom of the jump?

A projectile is fired at an angle of 30° above the horizontal from the edge of a vertical cliff. Ignore

air resistance. (a) Is the projectile’s velocity ever only horizontal? If so, when; if not, why not?

(b) Is its velocity ever only vertical? If so, when; if not, why not? (c) Are there any points at which

the projectile’s acceleration is either parallel or perpendicular to its velocity? Explain.

A compound gear train has a 30tooth driver gear A, machine with a 90tooth follower gear B, mounted on thesame shaft as Band attached to it's gear Cwith 60 teeth, machine with a gear D on the output shaft having 120teeth. Calculate the velocity ratio and mechanical advantage if the overall efficiency is 72%