Answer:
E ) The horizontal component of a projectile acceleration is zero.
Explanation:
In case of a projectile , force of gravity acts in vertically downward direction so acceleration will act in vertically downward direction . Its direction never changes during course of its journey. So horizontal component of acceleration will always be zero at all points of its journey.
The speed of the roller coater at the bottom of the hill is 31 m/s.
<h3>
Speed of the roller coater at the bottom of the hill</h3>
Apply the principle of conservation of mechanical energy as follows;
K.E(bottom) = P.E(top)
¹/₂mv² = mgh
v² = 2gh
v = √2gh
where;
- v is the speed of the coater at bottom hill
- h is the height of the hill
- g is acceleration due to gravity
v = √(2 x 9.8 x 49)
v = 31 m/s
Thus, the speed of the roller coater at the bottom of the hill is 31 m/s.
Learn more about speed here: brainly.com/question/6504879
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In the absence of gravity, t<span>he rocks and debris
would never accrete into a planet. (B)
Also by the way, it wouldn't matter much, because
there wouldn't be a star to orbit around, AND orbits
wouldn't exist either.</span>