Calculating Work and Force: Solving a Simple Amusement Park Problem

[Rha1828]

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.

Please any help would be great!

 

[sArGe99]

First find out the acceleration of the boat using kinematic data given...and calculate the force applied by Sam.

 

[Rha1828]

I don't understand how you would solve for acceleration.

 

[tiny-tim]

They are moving at a constant speed of 1.2 m/s … 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 …

I don't understand how you would solve for acceleration.

Hi Rha1828!

Just use one of the standard constant acceleration equations.

 

[LowlyPion]

Here are some kinematic equations that might help you out:
https://www.physicsforums.com/showpost.php?p=905663&postcount=2