(6) Wagon B is at rest so it has no momentum at the start. If <em>v</em> is the velocity of the wagons locked together, then
(140 kg) (15 m/s) = (140 kg + 200 kg) <em>v</em>
==> <em>v</em> ≈ 6.2 m/s
(7) False. If you double the time it takes to perform the same amount of work, then you <u>halve</u> the power output:
<em>E</em> <em>/</em> (2<em>t </em>) = 1/2 × <em>E/t</em> = 1/2 <em>P</em>
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When crest of one wave interferes with the trough of other wave, the amplitude of the resultant wave formed is less. Hence the type of interference is destructive interference.
In your question where as a golf ball is struck at a ground level and the speed of the ball as a function of time is in the figure where time t=0 and va = 16m/s and vb=32m/s. The following is the answer:
a) How far does the golf ball travel horizontally before returning to ground level?
-<span>80m</span>
<span>(b) What is the maximum height above ground level attained by the ball?
</span>-39.87m
Answer:
d) The 2 athletes reach the same height, because the athletes run with the same speed.
Explanation:
In the whole process , kinetic energy is converted into potential energy .
1/2 m v² = mgh
v² = 2gh
h = v² / 2g
In this expression we see that height attained does not depend upon mass of the object . At the same time it also makes it clear that it depends upon velocity . As the velocity in both the cases are same , height attained by both of them will be same. Hence option d ) is correct.
When the car comes to a stop, the final velocity must be 0 m/s.
Since the car js decelerating in a forward direction, acceleration must be negative.
final v = initial v + a•t
0 = 20 + (-6)t
t = 3.33s
