In the past, Earth has been hit by many asteroids, some very ...

[joe]

In the past, Earth has been hit by many asteroids, some very large. Suppose one such asteroid approached Earth so that when it was very far away it was traveling at 6500 m/s along a line that would miss the center of Earth by 8,500,000 m.
 
  Because of the gravitational attraction of Earth, it departed from this straight line and curved towards Earth, colliding with it. What was the speed of this asteroid when it hit Earth if we ignore the effect of the sun? The mass of Earth is 5.97  1024 kg, its radius is 6.38  106 m, and G = 6.67  10-11 N  m2/kg2.
  A) 11400 m/s
  B) 12900 m/s
  C) 13700 m/s
  D) 15800 m/s
  E) 16400 m/s

Question 2

A box of mass 72 kg is at rest on a horizontal frictionless surface. A constant horizontal force of magnitude F then is exerted on the box, accelerating it to the right. You observe that it takes the box 3.4 seconds to travel 13 meters.
 
  What is the magnitude of the force F?

[Hikerman221]

Answer to Question 1

B

Answer to Question 2

160 N

[joe]

Gracias!

[upturnedfurball]

Excellent