How Much Work Did Sam Do to Stop the Boat on the Ride?

[Rha1828]

Please help! Somple Work-energy problem!

Sam works at an amusement park. A boat of children on a water ride comes the the pier at the end of the ride. They are moving at a constant speed of 1.2 m/s, and the loaded boat has a mass of 1200kg. Sam slows the boat down by pushing on it until it comes to rest at the pier. If he stops it in a distance of 1.75m, and his arms make a 30o angle above the horizontal,

* a) how much work did Sam do on the boat?
* b) how large a force did he apply to the boat?


I thought if I added the mass X gravity that would five me force.
Then I took F cos theta X s to get 1.51 J
and the foce would be 11760.

I am not sure if that is right.

 

[myxomatosii]

Sam works at an amusement park. A boat of children on a water ride comes the the pier at the end of the ride. They are moving at a constant speed of 1.2 m/s, and the loaded boat has a mass of 1200kg. Sam slows the boat down by pushing on it until it comes to rest at the pier. If he stops it in a distance of 1.75m, and his arms make a 30o angle above the horizontal,

* a) how much work did Sam do on the boat?
* b) how large a force did he apply to the boat?


I thought if I added the mass X gravity that would five me force.
Then I took F cos theta X s to get 1.51 J
and the foce would be 11760.

I am not sure if that is right.

Why would you make two threads within an hour and a half of each other.

Perhaps anyone viewing this should go to

https://www.physicsforums.com/showthread.php?t=300950

I would also advice [for the sake of not being deleted] that you should probably only make one post on each topic and refine from there.

I am not a moderator, just a regular member trying to give you some friendly advice.

Thanks

 

[Rha1828]

Wow you are so helpful thanks! :)

 

[Evo]

Rha1828, it is against Forum policy to start duplicate threads.