The sign associated with the average velocity of the object is negative.
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Average velocity of the object</h3>
The average velocity of the object is calculated as follows;
Average velocity = (v1 + v2)/2
v1 = -20/30 = -0.667 m/s
v2 = 20/50 = 0.4 m/s
Average velocity = (-0.667 + 0.4)/2
Average velocity = -0.134 m/s
Thus, the sign associated with the average velocity of the object is negative.
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Answer:
Explanation:
Mass doesn't matter here because when something is falling, gravity plays fairly; an elephant falls at the same rate of acceleration as does a feather. What DOES matter is everything pertinent to the y-dimension of free-fall:
a = -9.8 m/s/s
v₀ = 0 (since the ball was held before it was dropped)
v = ??
Δx = -8 m (negative because the ball drops this far below the point from which it was released).
Putting all this together in one equation:
v² = v₀² + 2aΔx and filling in this equation:
v² = (0)² + 2(-9.8)(-8) and
v² = 156.8 so
v = 12.5 which rounds to 13 if you're using 2 sig figs, and rounds to 10 if you're only using 1 (which you should be, according to the way the numbers have been given in this problem)
It's D.
Weight always points downward.
The normal force always points perpendicular to the surface.
Friction opposes motion, so it points in the direction opposite the direction in which the block is moving.