A railroad car with a mass of 20,000 kg rolls into a second stationary car with a mass of 40,000 kg. The cars latch together and move off with a speed of 1.2 m/s. How fast was the first car moving before the collision?
3.6 m/s
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A(n) ______________ quantity has both magnitude and direction
Fill in the blank(s) with correct word
Angular Momentum: A merry-go-round spins freely when Diego moves quickly to the center along a radius of the merry-go-round. As he does this, it is true to say that
A. the moment of inertia of the system decreases and the angular speed increases. B. the moment of inertia of the system decreases and the angular speed decreases. C. the moment of inertia of the system decreases and the angular speed remains the same. D. the moment of inertia of the system increases and the angular speed increases. E. the moment of inertia of the system increases and the angular speed decreases.
The slope of a line connecting two points on a velocity versus time graph gives
A) displacement. B) instantaneous velocity. C) average velocity. D) instantaneous acceleration. E) average acceleration.
Why are ores so valuable?
A) They are sources of naturally occurring gold. B) Metals can be efficiently extracted from them. C) They tend to occur in scenic mountainous regions. D) They hold many clues to Earth's natural history.