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pogonyaev
3 years ago
14

An object is falling from a height of 7.5 meters. At what height will it’s velocity be 7 meters/second?

Physics
1 answer:
Nady [450]3 years ago
6 0
One of the equations of gravity is this:
{v}^{2} = {u}^{2} + 2gh
Where v = final velocity which is 7m/s
u = initial velocity which is 0 for objects falling from a height
g = acceleration due to gravity and it is approximately 10m/s^2. It's a constant so pretty much remember this number. It's positive since the work being done is caused by gravity (in other words, it's falling down). It can also be negative if the work being down is against gravity (in other words, it's going up)
h = height of object

Substitute for the values and you should have something like this
{7}^{2} = {0}^{2} + 2 \times 10 \times h
49 = 0 + 20h
h = \frac{49}{20}
h = 2.5m
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Answer:

D. 3 hours or more

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2 years ago
A wildebeest and chicken participate in a race over a 2.00km long course. the wildebeest travels at a speed of 16.0m/s and chick
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Answer:

(a)  The distance of the chicken from the finish line is 62.5 m

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Explanation:

Given;

total distance traveled by wildebeest and chicken, d = 2 km = 2000 m

speed of the wildebeest, v_w = 16 m/s

speed of the chicken, v_c = 2.5 m/s

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t = 800s - 125 s

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(a) how far (in m) is the chicken from the Finish Line when the wildebeest resume the race?

The time taken for the wildebeest to run 1.6 km (1600 m) is given by;

t = 1600 / 16 = 100 s

The total time spent by the wildebeest before it resumed the race = stationary time + 100s

t (total) = 675 s + 100 s = 775 s

Distnace traveled by the chicken when the wildebeest resumed the race = 2.5m/s x 775s = 1937.5 m

Thus, the distance of the chicken from the finish line = 2000 m -  1937.5 m

the distance of the chicken from the finish line = 62.5 m

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3 years ago
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3 0
2 years ago
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Answer:

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Explanation:

From the question,

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Ep = mgh............ Equation 2

Ek = 1/2mv²............. equation 3

Substitute equation 2 and equation 3 into equation 1

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Substitute into equation 4

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W = 235200000+562500000

W = 797700000 J

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