A 6.0-kg block slides along a horizontal surface. If µk = 0.20 for the block and surface, at what rate is the friction force changing the mechanical energy of the block at an instant when its speed is 4.0 m/s?
a. ?59 W
b. ?47 W
c. ?71 W
d. ?82 W
e. +71 W
b
You might also like to view...
Match the words in the left-hand column to the appropriate blank in the sentences in the right-hand column. Use each word only once.
A +5.0-nC charge is at the point (0.00 m, 0.00 m) and a -2.0-nC charge is at (3.0 m, 0.00 m). What work is required to bring a 1.0-nC charge from very far away to point (0.00 m, 4.0 m)? (k = 1/4??0 = 9.0 × 109 N ? m2/C2 )
A) 15 nJ B) 3.6 nJ C) 11 nJ D) 7.7 nJ
What do we mean by time dilation in relativity?
A) It is the idea that time seems to run slower in reference frames moving relative to you, but time really is the same for everyone. B) It is the idea that relativity makes time dilate, or expand, for people who study it. C) It is a hallucinogenic effect experienced by people who take too much of something. D) It is the idea that time really runs slower in reference frames moving relative to you.
Which is used observationally to determine the age of a star cluster?
A) the total number of main-sequence stars B) the luminosity of the main-sequence turn-off point C) the amount of dust that lies around the cluster D) the number of white dwarfs E) the ratio of giants to supergiants