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3 years ago

7

A bungee jumper attains a speed of 30 m/s just as the bungee cord begins to stretch. If the period of stretch is 2 s while comin

g to a halt, the jumper's average deceleration in gâ€™s is about ______?

1 answer:

Bogdan [553]3 years ago

4 0

Answer: $1.53g$

Explanation:

average deceleration= ?

inial velocity: $u=0$

final velocity: $v=30m/s$

time: $t=2seconds$

The first law of kinematics :

$v=u+at$

find a the subject of the formula

$a=v-u/ t$

$a=\frac{0-30} 2$

$a=-30/2$

$a=-15m/s^{2}$

The deceleration about g(acceleration due to gravity) will be:

$15/9.8$

$1.53g$

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Answer:

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Explanation:

In this case the kinetic energy of the bike is converted into the heat energy between the area of contact of tyre and the road. This happens due to the work done by the frictional force between the surface to stop the relative motion between the road and the tyre.

Given:

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(as given in the question that the rear tyre supports half the combined weight of the bike and the rider.)

distance dragged while stopping the tyre, $s=0.4\ m$

coefficient of kinetic friction between the surfaces, $\mu=0.8$

<u>Now, frictional force between the surfaces:</u>

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<u>Now, the work done by the kinetic friction:</u>

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$W=36\times 0.4$

$W=14.4\ J$

According to the energy conservation this amount of energy is converted into thermal energy between the surfaces in contact, i.e. road and the tyre.

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3 years ago

A vector is any quantity that has no units of measurement

djyliett [7]

False. Velocity is a vector and is measured in m/s (in SI, anyway).

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3 years ago

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Why is the law of gravity an example of a universal law?

Greeley [361]

Answer:

A

Explanation:

The most important part about this is not only that objects pull on each other, but that two objects attract each other with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between them. This is known as Newton's law of universal gravitation.

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If you answer this I will give you brainliest whoever answers first!!!

rusak2 [61]

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Explanation:

this graph show the decrease in velocity with time

at time t=0 velocity is 40 m/sec

at time t=12sec velocity is decreases from 40 to 10 m/s

so the acceleration of the object at time=12 sec is

a=v/t

a=Δv/t

Δv=v1-v2=40-10=30 m/s

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3 years ago

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stealth61 [152]

Answer:

7160.2812 s or 1.988 hours

Explanation:

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Force at equator would be

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From the question

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Time period is given by

$T=\dfrac{2\pi}{\omega}\\\Rightarrow T=2\pi\sqrt{\dfrac{2R}{g}}\\\Rightarrow T=2\pi\sqrt{\dfrac{2\times 6.37\times 10^6}{9.81}}\\\Rightarrow T=7160.2812\ s=1.988\ hours$

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