You are Here: Home >< Physics

A-level physics question on power. Watch

1. This was a question from a Unit 1 physics paper. I reaaaallly don't understand how we'd attempt this!!!

In the eighteenth century, James Watt manufactured steam engines. He needed a way to demonstrate the benefits of these compared to the horses they replaced. He did some calculations based on horses walking in circles to turn a mill wheel. Watt observed that a horse could turn the wheel 144 times in one hour. The horse travelled in a circle of radius 3.7 m and exerted a force of 800 N. Show that the work done by the horse in turning the wheel through one revolution was about 20 000 J.
2. (Original post by slaya)
This was a question from a Unit 1 physics paper. I reaaaallly don't understand how we'd attempt this!!!

In the eighteenth century, James Watt manufactured steam engines. He needed a way to demonstrate the benefits of these compared to the horses they replaced. He did some calculations based on horses walking in circles to turn a mill wheel. Watt observed that a horse could turn the wheel 144 times in one hour. The horse travelled in a circle of radius 3.7 m and exerted a force of 800 N. Show that the work done by the horse in turning the wheel through one revolution was about 20 000 J.
Well work done is force times distance and in this case that is 800 times 2 X pi X 3.7 Joules per revolution
3. (Original post by slaya)
This was a question from a Unit 1 physics paper. I reaaaallly don't understand how we'd attempt this!!!

In the eighteenth century, James Watt manufactured steam engines. He needed a way to demonstrate the benefits of these compared to the horses they replaced. He did some calculations based on horses walking in circles to turn a mill wheel. Watt observed that a horse could turn the wheel 144 times in one hour. The horse travelled in a circle of radius 3.7 m and exerted a force of 800 N. Show that the work done by the horse in turning the wheel through one revolution was about 20 000 J.
Overall workdone=force x distance. The force is 800N. so to calculate the distance the horse goes around a circle, therefore the perimeter of the circle is 2pi x radius. That gives you the distance travelled. therefore when you calculate it out you get an answer of 18598.22851J

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: May 12, 2016
Today on TSR

What is the latest you've left an assignment

And actually passed?

Simply having a wonderful Christmas time...

Discussions on TSR

• Latest
• See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Discussions on TSR

• Latest
• See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.