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Brut [27]
3 years ago
12

5. Your friend tosses a ball into the air. The equation h = -5ť + 30t +10 models the height,

Physics
1 answer:
Naily [24]3 years ago
4 0

Answer:

6.3s.

Explanation:

The height h is given by:

h(t)=-5t^2+30t+10

Setting the height h = 0 and using the quadratic formula to solve for t:

0=-5t^2+30t+10\\0=t^2-6t-2\\t_1=3-\sqrt{11}= -0.3s\\t_2=3+\sqrt{11}=6.3s

t₁ is physicly meaningless.

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Reptile [31]

speed of tortoise is given as v1 = 0.14 m/s

speed of hare is given as v2 = 20*0.14 = 2.8 m/s

now let say the total length of the path is "d"

so the total time taken by the tortoise to cover this

t = \frac{d}{0.14}

now given that hare took rest for 1 min

so total time of run for hare is (t - 60)s

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d - 0.30 = 2.8 * (t - 60)

now by above two equations

d - 0.30 = 2.8 * \frac{d}{0.14} - 168

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t = 63 s

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3 years ago
A jet engine gets its thrust by taking in air, heating and compressing it, and
nadya68 [22]

Answer:

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Explanation:

Thrust is known as a reaction force which appears when a system expels or accelerates mass in one specific direction. If we know the acceleration and the mass of the air expelled by the jet engine, we can compute the thrust .

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