1. What force keeps a satellite executing uniform circular motion around the Earth? a) gravity b) static friction c) normal d) tension 2. If a student walks 15 meters East and then he walks 15 meters North and his total trip takes 10 seconds, what is his average velocity? a) 0 m/s b) 2.12 m/s NE c) 3.00 m/s NE d) 21.2 m/s NE

3. A new car has a 0.040 m^3 volume gas tank. It also gets 20 km/L gas mileage. How far can the car go on a tank of gas? a) 8.0 km b) 20 km c) 800 km d) 2000 km

Search coils and credit cards. one practical way to measure magnetic field strength uses a small, closely wound coil called a search coil. the coil is initially held with its plane perpendicular to a magnetic field. the coil is then either quickly rotated a quarter-turn about a diameter or quickly pulled out of the field. (a) derive the equation relating the total charge q that flows through a search coil to the magnetic-field magnitude b. the search coil has n turns, each with area a, and the flux through the coil is decreased from its initial maximum value to zero in a time ∆t. the resistance of the coil is r, and the total charge is q = i∆t, where i is the average current induced by the change in flux. (b) in a credit card reader, the magnetic strip on the back of a credit card is rapidly “swiped” past a coil within the reader. explain, using the same ideas that underlie the operation of a search coil, how the reader can decode the information stored in the pattern of magnetization on the strip. (c) is it necessary that the credit card be “swiped” through the reader at exactly the right speed? why or why not?

Observations show that interstellar clouds can have almost any shape and

When measuring volume, why is it important to use the correct tools and units to attain the greatest accuracy? use specific examples from the lab to support your answer. (5 points)