The kinetic energy (KE) of a 0.155 kg arrow that is shot from ground level, upward at 31.4 m/s, when it is 30.0 m above the ground is 30.85 J
Assuming air friction is negligible,
a = - 9.8 m / s²
u = 31.4 m / s
s = 30 m
v² = u² + 2 a s
v² = 31.4² + ( 2 * - 9.8 * 30 )
v² = 985.96 - 588
v² = 397.96 m / s
KE = 1 / 2 m v²
KE = 1 / 2 * 0.155 * 397.96
KE = 0.0775 * 397.96
KE = 30.85 J
Therefore, the kinetic energy ( KE ) when it is 30.0 m above the ground is 30.85 J
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Answer:
Basically, at these speeds, the car will, at random times, swerve a bit to one side or the other as if hit by some huge wind (even on the calmest of days). It doesn't happen at slower speeds driving mechanically identical cars, managed to accelerate to a formidable 150 mph and stay there for most of the journey, shifting to higher gears and remaining.
Hope this helped you!
Explanation:
The distance from mile-mark 10 to mile-mark 115 is (115-10) = 105 miles.
Speed = (distance covered) / (time to cover the distance) .
Speed = (105 miles) / (1.75 hours)
Speed = (105/1.75) (mi/hr)
<em>Speed = 60 mph</em> (B)
Answer:
Height of tree = 78.35 meters.
Explanation:
We have
1 meter = 3.28 feet
That is

Here height of tree = 257 ft
Height of tree = 257 x 0.3048 = 78.35 m
Height of tree = 78.35 meters.