Author Question: With respect to the earth, object 1 is moving at speed 0.90 c to the right. Object 2 is moving to ... (Read 159 times)

DyllonKazuo · **on:** Jul 29, 2018

With respect to the earth, object 1 is moving at speed 0.90 c to the right. Object 2 is moving to the left at speed 0.70 c with respect to object 1. How fast is object 2 moving with respect to the earth?

A)

0.12 c
B)

-0.20 c
C)

0.54 c
D)

0.20 c
E)

1.6 c

Question 2

An object of mass 4 kg starts at rest from the top of a rough inclined plane of height 10 m as shown in Fig. 8-9.

If the speed of the object at the bottom of the inclined plane is 10 m/s, how much work is done by the force of friction? Use g = 10 m/s2. A)

-100 J

B)

100 J

C)

0

D)

-200 J

E)

200 J