2 Astronaut Rescue In outer space, high above the surface of Mars, a daring rescue is attempted as astronaut Mark Watney hurtles at 3 m/s relative to Commander Melissa Lewis who holds on to one end of an effectively massless tether. When Watney reaches the tether he is traveling perpendicularly to it and is 5 m from Lewis; each of them have a mass of 80 kg. Problem 2.1. In the CoM reference frame for this system, what are the speeds of each astronaut when Watney reaches the tether? Problem 2.2. What is the angular momentum of the two astro- nauts about the гCOM? Problem 2.3. If Watney catches the tether, how much force FLewis must Lewis exert to pull on the tether as the two astronauts begin orbiting their CoM? Problem 2.4. To rescue him, Commander Lewis then pulls in the tether until she and Watney are only separated by 0.5m. What force does she then have to exert on the tether at this point? 3 m/s

A weather forecast states that the temperature is predicted to be -5°C the following day. Is this temperature a vector or a scalar quantity? Explain.

The CERN particle accelerator is circular with a circumference of 7.0 km. (a) What is the acceleration of the protons (m=1.671027kg)that move around the accelerator at 5of the speed of light? (The speed of light is v=3.00108m/s .) (b) What is the force on the protons?

Two speedboats are traveling at the same speed relative to the water in opposite directions in a moving river. An observer on the riverbank sees the boats moving at 4.0 m/s and 5.0 m/s. (a) What is the speed of the boats relative to the river? (b) How fast is the river moving relative to the shore?

In the blizzard of ’88, a rancher was forced to drop hay bales from an airplane to feed her cattle. The plane flew horizontally at 160 km/hr and dropped the bales from a height of 80 m above the flat range, (a) She wanted the bales of hay to land 30 m behind the cattle so as to not hit them. Where should she push the bales out of the airplane? (b) To not hit the cattle, what is the largest time error she could make while pushing the bales out of the airplane? Ignore air resistance.

In an attempt to escape a desert island, a castaway builds a raft and sets out to sea. The wind shifts a great deal during the day, and she is blown along the following straight lines: 2.50 km and 45.0 north of west, then 4.70 km and 60.0 south of east, then 130 km and 25.0 of west, then 5.10 km due east, then 1.70 km and 5.00 east of north, then 7.20 km and 55.0 south of west, and finally 2.80 km and 10.0 north of east. Use the analytical method to find the resultant vector of all her displacement vectors. What is its magnitude and direction?

Try the following experiment away from traffic: where you can do it Safely. With the car VOU are driving moving slowly on a Straight, level road, shift the transmission into neutral and let the car coast. At the moment the car comes to a complete slop, step hard on the ln.ike and notice what you feel. Now repeal I he same experiment on a fairly gentle, uphill slope. Explain the difference in what a pet son tiding in the car feels in the two cases. (Brian Popp suggested the idea for this question.)

A dime is placed at the edge of a table so it hangs over slightly. A quarter is slid horizontally on the table surface perpendicular to the edge and hits the dime head on. Which coin hits the ground first?

Check Your Understanding A boat heads north in still water at 4.5m/s directly across a river that is running east at 3.0 m/ s. What is the velocity o the boat with respect to Earth?

Suppose that a person takes 0.5 s to react and move his hand to catch an object he has dropped. (a) How far does the object tall on Earth, where g=9.8m/s2 ? (b) How far does the object fall on the Moon, where the acceleration due to gravity is 1/6 of that on Earth?