Consider a monkey wrench released at rest at the far edge of the solar system. Suppose that it drops to Earth by virtue of only Earth's gravity. The wrench will strike Earth's surface with a speed of about
A)10 m/s.
B)8 km/s.
C)11 km/s.
D)the speed of light.

Question

Quizplus · Accepted Answer

The wrench will experience an acceleration due to gravity of 9.81 m/s^2 as it falls toward Earth. Using the equation v^2 = u^2 + 2as, where u = 0 m/s (initial velocity), a = 9.81 m/s^2 (acceleration due to gravity), and s = the distance from the far edge of the solar system to Earth's surface (about 149.6 million km), we can solve for v (the final velocity):
v^2 = 0 + 2(9.81 m/s^2)(149.6 x 10^6 m)
v^2 = 2.93 x 10^15
v = sqrt(2.93 x 10^15) = 5.41 x 10^7 m/s
Converting to km/s, we get approximately 11 km/s, which is closest to choice C.

Consider a Monkey Wrench Released at Rest at the Far