1. 40 mph v'= 25 mph If the observed horizontal speed of the B  A volley on board is v'=25mph then stationary observers on the train platform, see it travel with a speed (1) -25 mph(3) 15 mph(5) 40 mph (2) -15 mph(4) 25 mph(6) 65 mph

2. 40 mph v'=  25 mph If the horizontal speed of the return (A  B) volley is v'=  25mph then stationary observers on the train platform see the ball’s speed as (1) -25 mph(3) 15 mph(5) 40 mph (2) -15 mph(4) 25 mph(6) 65 mph

3. 40 mph v'=  40 mph What if v'=  40mph?

4. 5 m/sec Frame v2 B =3 m/sec 1 kg v1 B =0

5. u Frame a m d Within Frame B a mass, m, is accelerated from rest by a force F through a distance d.

6. ConcepTest In Galilean or Newtonian Relativity, which of the quantities below change when you change your reference frame? 1)velocity 2)distance 3)mass 4) acceleration 5) all of the above 6) 1 and 2 only

7. ConcepTest 1) time 2) mass 3) force 4) all of the above 5) none of these In Galilean or Newtonian Relativity, which of the quantities below change when you change your reference frame?

8. How do you tell when you are completely stopped?

9. horizontal speed of the B  A volley (6) 65 mph horizontal speed of the A  B volley (3) 15 mph The common sense rule you apply is Though according to spectators on board the train volleys are simply left-right-left-right-left-right-left… the ground-based observers actually see the ball always traveling left, but: fast-slow-fast-slow-fast-slow-fast… (6) 1 and 2 only Sure mass doesn’t seem to be something affected by being in a moving compartment. But if velocity is, why wouldn’t acceleration be? Recall the definition: a=  v/  t =(v final -v initial )/  t. Since v A final = v B final + V rel and v A initial = v B initial + V rel then  v A =  v B ! 5) none of these We call such absolute quantities invariant.