Two masses are connected by a light string passing over a light, frictionless pulley as in Figure P5.63. The m1 = 5.45 kg object is released from rest at a point 4.00 m above the floor, where the m2 = 2.55 kg object rests.
Figure P5.63
(a) Determine the speed of each object when the two pass each other.
3.80 m/s
(b) Determine the speed of each object at the moment the 5.45 kg mass hits the floor.
5.33 m/s
(c) How much higher does the 2.55 kg mass travel after the 5.45 kg mass hits the floor?
m
thank you for your help!
2006-10-04 16:54:35 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Physics
5.45m above the ground
When the 5.45kg mass first hits the floor, it has travelled 4m downwards. Connected in the same system m2 will move 4.0m upwards from the ground.
At the point when the heavier mass hit the ground, both masses have a speed of 5.33m/s (in different directions)
While the energy from the heavier mass is transferred to the ground, the energy of the lighter mass gets potential energy.
Since
Kinetic energy lost = Potential energy gained
1/2(2.55)(5.33)^2 = (2.55)(9.81)(h)
h = 1.45
total distance above ground = 4.0 + 1.45 = 5.45m
2006-10-05 02:56:19 · answer #1 · answered by clandestiny 2 · 0⤊ 0⤋
Since both of them are connected the force on m2 will exist till m1 reaches the ground.
As soon as m1 reaches the ground, the velocity acting on it is 5.33m/s as you have already calculated. All the kinetic energy it possesses is converted into potential energy because there is no more force acting on m2 after m1 reaches the ground.
0.5mv^2 = mgh ( h= height travelled).... also m gets cancelled from both sides
0.5 (5.33)^2 = (9.81)(h)
thus, h = (0.5 (5.33)^2) / 9.81
finally calculate 'h'
the answer will read: " The body will travel 'h' m aboe 4 m from the ground.
My verbal explanation is not that good sorry about that. I hope you have understood my solution steps.
I wish I have helped you right.
2006-10-05 02:24:09 · answer #2 · answered by Sindhoor 2 · 0⤊ 0⤋
You would be finding when the 2.55kg mass's vertical velocity is zero, because it has accelerated upward, thus when the 5.45kg mass hits the floor, the other mass is still accelerating up, until it is stopped by the acceleration due to gravity. At the time it stops, velocity is zero.
2006-10-05 00:57:34 · answer #3 · answered by MJPM 2 · 0⤊ 0⤋
Since you know the velocity, use conservation of energy to solve it. The kinetic energy is converted to potential energy.
2006-10-05 00:22:00 · answer #4 · answered by daedgewood 4 · 0⤊ 0⤋
sorry i cant help
i learned this thing just yesterday
tell me if it is not hard
2006-10-04 23:59:47 · answer #5 · answered by Forrest T 1 · 0⤊ 0⤋