1
PHY 2020
Homework Set #1
Fall 2014
Due: At the start of class on Aug 27, 2014. (Not 5 minutes after the start of class.)
If you just give an answer without showing how you arrived at that answer, then you will
get no credit for the problem.
Name:
These facts might be useful: 1 kg = 2.2 lbs, and 1 m = 39 inches. These are close enough
to be used in any reasonable application.
1. What is your height in inches? What is your height in centimeters?
For the first question just write down what your height might be.
2. What is your weight in pounds? What is your weight in kilograms?
Similarly, just write down what your weight might be.
3. If you run at 10mph (ten miles per hour), then what is your speed in m/s?
4. The Earth rotates once in 24 hours. First find the circumference of the Earth, and
then determine how fast you would be moving around the axis of the Earth if you
were quietly sitting on the equator.
√
5. What is a good approximation for 1 − 1 − 3 × 10−30 ?
Hint: Your calculator probably won’t help very much.