# Physics

posted by .

Imagine that a person is seated in a chair that is suspended by a rope that goes over a pulley. The person holds the other end of the rope in his or her hands. Assume that the combined mass of the person and chair is M.
What is the magnitude of the downward force the person must exert on the rope to raise the chair at a constant speed? Express your answer in terms of M and g. (Hint: the answer is not Mg!)
What is the magnitude of the required force if the person is accelerating upward with mag(a âƒ‘)=0.10g?â€ƒ

• Physics -

The tension in the rope acts upwards with respect to the chair and upwards with respect to the force of the man's hands. Both tension forces are equal and in the same direction. Ma=-Mg+tension1+tension2. Tension 1 and 2 are equal so the equation reads Ma=-Mg+2tension so Ma+Mg=2F(t) so M(a+g)/2=F. The chair moves at a constant speed so acceleration is zero implying 1/2(Mg)=F(t).

## Similar Questions

1. ### PHYSICS - plz help

A house painter uses a chair and pulley arrangement to lift himself up the side of a house. The painter's mass is 69.2 kg and the chair's mass is 24.0 kg. With what force must he pull down on the rope in order to accelerate upward …
2. ### Physics

What is the tension in the rope of this figure description?
3. ### physics

What is the tension in the rope of this figure description?
4. ### physics

A rope goes over a circular pulley with a radius of 6.3 cm. If the pulley makes four revolutions without the rope slipping, what length of rope passes over the pulley?
5. ### physics

there is a massless rope that is pulled over a frictionless pulley that is suspended high above the ground one end of the rope is tied to a heavy block with a mass of 483 kg the free end is climbed by a person with a mass of 102 kg …
6. ### physics

a person attaches a 25kg hay bale to one end of a rope passing over a frictionless pulley connected to a beam in the hay barn. another person then pulls down on the opposite end of the rope with a force of 277-N Ignoring the mass of …
7. ### Physics

2 people, each with a mass of 70 kg, are wearing inline skates and are holding opposite ends of a 15 m rope. One person pulls forward on the rope by moving hand over hand and gradually reeling in more of the rope. In doing so, he exerts …
8. ### Physics

A rope goes over a circular pulley with a radius of 5.5 If the pulley makes 6 revolutions without the rope slipping, what length of rope passes over the pulley?
9. ### physics

The combined mass of a man and a chair suspended at the midpoint of a rope of negligible mass is 50 kilograms. The rope is connected to a weight of 4360 newtons hanging from a massless frictionless pulley. Find the angle.
10. ### PHYSICS

tWO PEOPLE PLAY TUG OF WAR. tHE 97 KG PERSON ON THE LIFT PULLS WITH 1,176 n, AND THE 76 KG PERSON ON THE RIGHT PULLS WITH 839 n. aSSUME THAT NEITHER PERSON RELEASES THEIR GRIP ON THE ROPE WITH EITHER HAND AT ANY TIME, ASSUME THAT THE …

More Similar Questions

Post a New Question