# Homework Help: See if you can solve this tough one (energy and momentum)

1. Jul 1, 2009

### jmb07

See if you can solve this tough one!! (energy and momentum)

Castle, which are found on the loch's western shore. A truck carrying barrels passes and, as it does, a
sealed barrel and a spare lid fall from the truck and land by the side of the road. The barrel comes to
rest at the very top of the snowy slope that leads down to the loch's shoreline. A few moments later, the
wind from the next car is just enough to push the barrel over the edge to slide, not roll, down the slick
slope. Once the barrel reaches the bottom, it begins to roll across the level shore. It rolls over exactly 3
times before rolling into a tree branch at the water's edge. Upon hitting the branch, the barrel is
knocked up and into the air, at what appears to be a 45 degree angle. It flies through the air for about 2
seconds before landing in the water. After it is in the water for a few moments, you notice that the
barrel is floating right side up with about half of it above the surface. To your astonishment, a small
aquatic creature, the likes of which you have never seen, begins to play with the barrel. Following one
particularly strong nudge to the barrel, which leaves the barrel bobbing up and down in the water, the
creature is scared away by shouts from other tourists. After recording that the barrel bobs up and down
once every 1.36 seconds you walk along the road to further investigate what you have just witnessed.
Your investigation reveals that the mass of the spare lid is 6.8 kg, the road is 14m above the shore, and
that distance from the bottom of the slope to the water's edge is 5.4m.
Now, you have enough information to answer a very important question, namely, was there any
whiskey in the barrel and, if so, how much?
HINT: You should assume that energy is conserved until the barrel enters the water.

2. Jul 1, 2009

### jmb07

Re: See if you can solve this tough one!! (energy and momentum)

forgot this at the beggining:
One winter break, while visiting Scotland's Loch Ness, you stop to tour the ruins of Urquhart

3. Jul 1, 2009

### RoyalCat

Re: See if you can solve this tough one!! (energy and momentum)

Are you supposed to assume that the mass of the spare lid is equal to the mass of an empty barrel?