# physics

posted by .

A pendulum is initially displaced to a height 1 y above the table
top, as in figure 1. It is released with an initial speed of 1 v = 0 . At
the lowest point of its motion, it is at a height 2 y above the
table top, and with a speed of 2 v . Derive an equation of 2 v , in
terms of 1 y and 2 y , assuming that its total mechanical energy is
conserved.

• physics -

Can you double check if figure 1 looks like this:
http://img823.imageshack.us/img823/6783/1282485265.png

If this is the case, then
equate energies, namely potential and kinetic energies:
Change in potential energy, ΔEp=mg(y2-y1)
Change in kinetic energy, ΔEk=(1/2)m(v2²-v1²)

By the law of conservation of energy, we have
ΔEp+ΔEk=0
Substitute and solve for v2, noting that v1=0.

## Similar Questions

1. ### physics

The length of a simple pendulum is 0.82 m and the mass of the particle (the "bob") at the end of the cable is 0.69 kg. The pendulum is pulled away from its equilibrium position by an angle of 6.7 ° and released from rest. Assume that …
2. ### Physics (3)

The mass m=1.00 kg is set up as a pendulum of length 0.6m . Initially in the position of h=0.2 m above the lowest point, and the pendulum is given initial speed of 1.00 m/s. What is the largest mass M that could be temporarily lifted …
3. ### Physics

The pendulum bobs in the figure are made of soft clay so that they stick together after impact. The mass of bob B is 14 times that of bob A. Bob B is initially at rest. If bob A is released from a height h above its lowest point, what …
4. ### Physics

An object of mass 2 kg is attached to a string to form a pendulum. It is initially displaced to a height of 10 cm above the lowest point and let go. It hits another object of mass 1 kg at its lowest point. Given that the collision …
5. ### Physics

A 0.60 kg mass is attached to a 0.6 m string and displaced at an angle of 15 degrees before it is released. 1)What is the potential energy of the pendulum?
6. ### Physics

A 0.60 kg mass is attached to a 0.6 m string and displaced at an angle of 15 degrees before it is released. 1)What is the potential energy of the pendulum?
7. ### College Physics

A 0.60 kg mass is attached to a 0.6 m string and displaced at an angle of 15 degrees before it is released. 1)What is the potential energy of the pendulum?
8. ### College Physics

A 0.60 kg mass is attached to a 0.6 m string and displaced at an angle of 15 degrees before it is released. 1)What is the potential energy of the pendulum?
9. ### Physics

A 0.60 kg mass is attached to a 0.6 m string and displaced at an angle of 15 degrees before it is released. 1)What is the potential energy of the pendulum?
10. ### physics question

A 2kg mass is attached to a 5.50m long string. The mass is pulled 30 degrees from its lowest point and then released. What is the initial height of the pendulum above its lowest point?

More Similar Questions