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Tarzan and Jane, whose total mass is 115.0 kg, start their swing on a 5.0 m long vine when the vine is at an angle of 30.0° with the horizontal. At the bottom of the arc, Jane, whose mass is 50.0 kg, releases the vine. What is the maximum height at which Tarzan can land on a branch after his swing continues? (Hint: Treat Tarzan's and Jane's energies as separate quantities.)

Relevant equations:

1/2mv^2

mgh

sin, cos

I know that after she jumps, the energy is the same (conserved)

but how do i solve for height? The mass is less and that got me confused since gravity affects the height.

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2.

An 85.0 N box of clothes is pulled 17.0 m up a 30.0° ramp by a force of 115 N that points along the ramp. If the coefficient of kinetic friction between the box and ramp is 0.22, calculate the change in the box's kinetic energy.

KEi + PEi = KEf + PEf + Wfnc

1/mv^2

mgh

sin, cos

I started this pretty well, but here is what happened:

I calculated the components of the incline and got the parallel force and the perpendicular force. So from that i got the Normal force and then i used Fn * u to get Ffr and i multiplied that by 17, to get Wfnc.

but the problem is what i have to do with the net force, since there is 115 N-ffr-parallel force

and would PEi and KEf be zero? are we supposed to assume that?

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# Homework Help: Question on Conservation of Energy

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