Please solve the following problems. You must show all work for full/partial credit. When complete, attach a typed cover sheet and submit to the assignment drop-box. Take sig figs into account in ALL problems! Use scientific notation with sig figs in your answers.

#1. One lightyear is defined to be the distance light can travel in one year. (10 points)

• What is this distance in meters?
• How long does it take for light to get to the Moon from the Earth?

#2. Multiply 1.783 x 10² * 4.4 x 10^-3, taking into account significant figures. (10 points)

#3. What is the surface area of a sphere of diameter 2.4 x10² cm? (10 points).

#4. What is larger 4000 L or 4 x 10⁵ cm³ (and you must show your reasoning.) (10 points)

#5. A car travels 120 meters in one direction in 20 seconds. Then the car returns ¾ of the way back in 10 seconds. (10 points)

• Calculate the average speed of the car for the first part of the trip.
• Find the average velocity of the car.

#6. A sports car moving at constant speed travels 150 m in 4.00 s. If it then brakes and comes to a stop while decelerating at a rate of 6.0 m/s² how much time does it take to stop? (20 points)

#7. Explain a possible situation where you start with a positive velocity that decreases to a negative increasing velocity while there is a constant negative acceleration. (10 points)

#8. A stone is dropped from the roof of a high building. A second stone is dropped 1.25 s later. How long does it take for the stones to be 25.0 meters apart? SHOW ALL WORK! Hint: you need to write out an equation of motion for each stone and note that their separation depends on the common time you seek to answer.(20 points).