# physics

posted by .

An 82 kg man lowers himself to the ground from a height of 6.6 m by holding onto a rope that runs over a frictionless pulley to a 66 kg sandbag. With what speed does the man hit the ground if he started from rest?

• physics -

Force up on 66 kg mass = T
Force down on 66 kg mass = 66(9.8 )
net force up on 66 kg = T-66(9.8)
F = m a
T -66(9.8) = 66 a
a is down

Force down on 82 kg mass = 82(9.8)
Force up on 82 kg mass = T
net force down on 82 kg = 82(9.8) -T
F = m a
82(9.8) - T = 82 a
(82-66)(9.8) = (82+66) a
solve for a which is down
then
6.6 = (1/2) a t^2
solve for t
then v = a t

## Similar Questions

1. ### pulley and rotation

Two masses, mA = 35.0 kg and mB = 42.0 kg, are connected by a rope that hangs over a pulley (as in the figure). The pulley is a uniform cylinder of radius 0.50 m and mass 4.8 kg. Initially mA is on the ground and mB rests 2.5 m above …
2. ### Physics helppp

Figure 5-53 shows a man sitting in a bosun's chair that dangles from a massless, frictionless pulley and back down to the mans's hand. The combined mass of man and chair is 94 kg. Fig. 5-53 With what force magnitude must the man pull …
3. ### physics

Figure 5-53 shows a man sitting in a bosun's chair that dangles from a massless rope, which runs over a massless, frictionless pulley and back down to the man's hand. The combined mass of man and chair is 95.4 kg. With what force magnitude …
4. ### science

A 80.0 kg girl lowers herself to the ground from a height of 11.6 m by holding onto a rope running over a pulley to a 56.0 kg sandbag. What is the magnitude of the acceleration of the girl?
5. ### physics

A man is standing on a platform that is connected to a pulley arrangement, as the drawing shows. By pulling upward on the rope with a force the man can raise the platform and himself. The total mass of the man plus the platform is …
6. ### physics

A man is standing on a platform that is connected to a pulley arrangement, as the drawing shows. By pulling upward on the rope with a force the man can raise the platform and himself. The total mass of the man plus the platform is …
7. ### MATH

A MAN GRASP A ROPE 6M ABOVE THE GROUND, FROM HIS HAND THE ROPE GOES STRAIGHT UP TO A PULLEY 36M ABOVE THE GROUND AND THEN STRAIGHT DOWN TO THE WEIGHT RESTING ON THE GROUND. IF THE MAN, HOLDING FAST TO A ROPE AND KEEPING HIS HAND 6M …
8. ### Physics

Using a simply pulley/rope system, a crewman on an Arctic expedition is trying to lower a 6.17-kg crate to the bottom of a steep ravine of height 23.8 meters. The 55.6-kg crewman is walking along holding the rope, being careful to …
9. ### Physics

Using a simply pulley/rope system, a crewman on an Arctic expedition is trying to lower a 6.17-kg crate to the bottom of a steep ravine of height 23.8 meters. The 55.6-kg crewman is walking along holding the rope, being careful to …
10. ### physics

A man is standing on a platform that is connected to a pulley arrangement, as the drawing shows. By pulling upward on the rope with a force   the man can raise the platform and himself. The total mass of the man plus the platform …

More Similar Questions