Mechanics | Relativity Answers

Fundamental mechanics

Ali bicycles to a place 20km away. John's route to the same place is 4km longer but he rides 2km/h faster than Ali and gets their 5mins later. What are their speeds?

How much force must be exerted through the wire rope that moves the car in an elevator given that the car masses 501kg and there are 7 people average mass 75 kg and that the friction in the guide along the shaft average 205N. when
a) the car is accelerating upward at 1.00m/s^2?
b) the car is moving upward and slowing down at the equivalent rate?

1. a) What is the weight of a railway car of mass 70 T. ? b) Given that a force of 700 N. will just keep this car rolling, what is the coefficient of rolling friction?

A mass of 5kg is on top of a building of height 10m. Calculate its potential energy.
The mass then falls at a speed of 8 m/s in 4 sec, find its KE and momentum p. What is the Force and impulse the mass transfers to the ground?

part 1- A mass of 5KG is on top of a building of heights 10M calculate its potential energy the mass then falls at a speed of 8M/S in 4 seconds find its KE and momentum P what is the force and impulse the mass transfers to the ground

part-2- For the above problem find the work done by gravity if the mass falls a distance of 2 meters if the mass falls for 11 seconds what is the energy expanded by this force?

A 1200 kg car downhill speeds from rest to 2.4m/s² (acceleration) uphill in 14 seconds to reach the top of the hill. The height of the hill is 48m. If the car is 31% efficient, how much energy did the car use?

A. A mass of 5kg is on too of a building of height 10m. Calculate its potential energy.
B. The mass then falls at a speed of 8m/s in 4 secs, find its KE and momentum p. What is the force and impulse the mass transfers to the ground?
C. What is the work done by gravity if the mass falls a distance 2 meters. If the mass falls for 11 seconds, what is the energy expended by this force?

A. A mass of 5kg is on too of a building of height 10m. Calculate its potential energy.
B. The mass then falls at a speed of 8m/s in 4 secs, find its KE and momentum p. What is the force and impulse the mass transfers to the ground?

A body falls freely undergravity from a height of 40m into the top of a platform 0.8m above the ground. It velocity on reaching the platform is_______. Take g=9.8m/s