A 4.0 kg box of fruit slides 8.0 m down a ramp, inclined at 30. ...

[bcretired]

A 4.0 kg box of fruit slides 8.0 m down a ramp, inclined at 30. from the horizontal. If the box slides at a constant velocity of 5.0 m/s, the work done by gravity is
 
  A) +78. J.
  B) 0.16 kJ.
  C) -78. J.
  D) zero.
  E) -0.16 kJ.

Question 2

Modern mammals are descendants of
 
  A) birds that were able to survive the impact that wiped out the dinosaurs 65 million years ago
  B) sea animals that colonized the land after the impact that wiped out the dinosaurs 65 million years ago
  C) early mammals that lived under the ground that were able to survive the impact that helped to wipe out the dinosaurs 65 million years ago
  D) early mammals that killed off the dinosaurs

[jessofishing]

Answer to Question 1

B

Answer to Question 2

C

[bcretired]

Excellent

[isabelt_18]

Gracias!