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3 years ago

A girl on a bridge throws a rock

Physics

1 answer:

Anon25 [30]3 years ago

6 0

t = 1.3 s.

To solve this exercise we have to use the freefall equation t = (v-v₀)/g. v = 0 due the final velocity when the rock reach the ground is 0.

With v₀ = -12.5m/s and g = 9.8m/s²

t = -(-12.5m/s)/9.8m/s²

t = 1.3 s

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Which event is an example of melting?

qaws [65]

Answer:

welding metal

Explanation:

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2 years ago

A man stands on a platform that is rotating (without friction) with an angular speed of 1.0 rev/s; his arms are outstretched and

Airida [17]

Answer:

Explanation:

Given

$N_1=1 rev/s$

angular velocity $\omega =2\pi N_1=6.284 rad/s$

Combined moment of inertia of stool,student and bricks $=6\ kg.m^2$

Now student pull off his hands so as to increase its speed to suppose $N_2$ rev/s

$\omega _2=2\pi N_2$

After Pulling off hands so final moment of inertia is

$I_2=2\ kg-m^2$

Conserving angular momentum as no external torque is applied

$I_1\omega _1=I_2\omega _2$

$6\times 6.284=2\times \omega _2$

$\omega _2=18.85\ rad/s$

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7 0

3 years ago

Astronaut Sarah leaves Earth in a spaceship at a speed of 0.280c relative to Earth. Sarah's destination is a star-system 12.5 li

Usimov [2.4K]

Answer:

L= 12 light years

Explanation:

for length dilation we use the formula

$L=L_0\sqrt{1-\frac{v^2}{c^2} }$

now calculating Lo

Lo = 12.5×365×24×3600×3×10^8

= 1.183×10^17 m

now putting the values of v and Lo in the above equation we get

$L=1.183\times10^{17}\sqrt{1-\frac{0.28c^2}{c^2} }$

= 1.136×10^17 m

L= $= \frac{1.136\times10^{17}}{365\times24\times3600\times3\times10^8}$ m

so L= 12 light years

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3 years ago

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BigorU [14]

Answer:

B) how steep the slope is

Explanation:

Because you have to know how is the influence of the steep of the slope in the time that a ball reaches the bottom. The steep of the slope is the variable that you would have to change in an experiment.

I hope this is useful for you

regards

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2 years ago

10. A loud motorcycle passes by the front of Bill's house. What medium

garik1379 [7]

Answer: Air

Explanation:

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2 years ago

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