Mechanics | Relativity Answers

A 3000 kg elevator rises from rest in the basement to the floor. A distance of 25m . As it passes the fourth floor it's speed is 3 m/s . There's a constant frictional force of 500N. Calculate the work by the lifting mechanism?

Roger sees water balloons fall past his window. He notices that each balloon strikes the sidewalk 0.59 s after passing his window. Roger's room is on the second floor, 10 m above the sidewalk.

How fast are the balloons traveling when they pass Roger's window?

Assuming the balloons are being released from rest, from what floor are they being released? Each floor of the dorm is 5.0 m high.

Roger sees water balloons fall past his window. He notices that each balloon strikes the sidewalk 0.59 s after passing his window. Roger's room is on the second floor, 10 m above the sidewalk.

How fast are the balloons traveling when they pass Roger's window?

Assuming the balloons are being released from rest, from what floor are they being released? Each floor of the dorm is 5.0 m high.

Suppose you adjust your garden hose nozzle for a fast stream of water. You point the nozzle vertically upward at a height of 1.8 m above the ground (. When you quickly turn off the nozzle, you hear the water striking the ground next to you for another 2.6 s .

What is the water speed as it leaves the nozzle?

A railway truck of 100kg mass traveling with a velocity of 7ms^-1collides with a second truck of 200kg mass and the two couple automatically and move off together. Calculate the velocity of the coupled trucks and the energy lost to the system; if the second truck has a speed of 5ms^-1(a) in the same direction, (b) in the opposite direction and (c) is initially stationary.

The average angular acceleration of a stone lodged in a rotating car wheel is 100 rads .What will the stone’s final angular speed be after 3.0 s, if it starts

From rest? Also calculate its angular displacement during this time.

A satellite of mass 200 kg is displaced by a distance of

2RE

from a point on the

Earth’s surface, where

RE

is the radius of the Earth. Calculate the work done on

the satellite by the force of gravitation. Take the values of the constants in your

calculation from the astrophysical data given in the course

 Why can’t you establish whether you are running a high temperature by touching your own forehead?

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?