What is the input force needed to push a 1580 newton snowmobile up a 2.5 long board into the back of a pick-up truck. the bed of the pickup is 1.10 meters high and the board is 80% efficient?

869 Newtons.

What's the gain in Gravitational Potential Energy in this process?

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What's the energy input in this process?

The output of the board is the same as the gain in gravitational potential energy, 1738 Joules.

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explanation:

v=uf/(u-f)

= 5.-10/(5+10) convex lens has negative focal length

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s