Full Revolutions of a Round Rock Rolling Downhill

How many full revolutions will a round rock complete if it rolls 2 km downhill?

A) 243

B) 248

C) 318

D) 327

Answer:

The correct answer is A) 243

When a round rock with a circumference of 8.2 m rolls 2 km downhill, it will complete 243 full revolutions. To calculate the number of full revolutions, we need to convert the downhill distance to the distance traveled along the circumference of the rock.

First, we convert 2 km to meters: 2 km = 2,000 m.

Next, we divide the downhill distance by the circumference of the rock to find the number of full revolutions: Number of revolutions = 2,000 m / 8.2 m ≈ 243.9.

Since the number of full revolutions should be a whole number, the round rock will complete 244 full revolutions when rolling 2 km downhill. Therefore, the correct answer is A) 243.