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3 years ago

When will an object dropped from rest attain a speed of 30 m/s?

Physics

1 answer:

stich3 [128]3 years ago

8 0

<h3><u>Answer</u> :</h3>

Initial velocity = zero (i.e., free fall)

Final velocity = 30m/s

Acceleration due to gravity = 10m/s²

For a body falling freely under the action of gravity, g is taken positive $.$

◈ <u>First equation of kinenatics</u> :

⇒ v = u + gt

⇒ 30 = 0 + 10t

⇒ t = 30/10

⇒ <u>t = 3s</u>

Hence, object will attain a speed of 30m/s after 3s.

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The seismic activity density of a region is the ratio of the number of earthquakes during a given time span to the land area aff

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Answer:

0.0059

Explanation:

According to the question the seismic activity density is given by

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Here,

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The seismic activity density is 0.0059

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3 years ago

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You get hit in the head with a baseball as it is falling. What are the action and reaction forces?

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Answer:

Action: Gravity pulls on the ball.

Reaction: The ball falls to the ground.

Explanation:

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2 years ago

The perimeter of a rectangle can be found using the equation P = 2L + 2W, where P is the perimeter, L is the length, and W is th

sweet [91]

Answer:

The perimeter of the rectangle is 60 units.

Explanation:

The perimeter of a rectangle is given by the equation P = 2L + 2W. With W = 12 units and L = 18 units, substituting the values in the equation above:

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3 years ago

a large parallel plate capacitor has plate seperation of 1.00 cm and plate area of 314 cm^2. The capacitor is connected across a

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Answer:

$W = -2.76\times 10^{-9}~J$

Explanation:

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The potential energy is given by the following formula:

$U = \frac{1}{2}CV^2$

where C can be calculated using the plate separation and area.

$C = \epsilon\frac{A}{d} = \epsilon\frac{0.0314}{0.01} = 3.14\epsilon$

Therefore, the potential energy in the first case is

$U = \frac{1}{2}3.14\epsilon (20)^2 = 628\epsilon$

In the second case:

$C_2 = \epsilon\frac{A}{d} = \epsilon\frac{0.0314}{0.02} = 1.57\epsilon\\U = \frac{1}{2}C_2 V^2 = \frac{1}{2}1.57\epsilon (20)^2 = 314\epsilon$

The permittivity of the air is very close to that of vacuum, which is 8.8 x 10^-12.

So, the difference in the potential energy is

$W = U_2 - U_1 = \epsilon(314 - 628) = -314 \times 8.8 \times 10^{-12} = -2.76\times 10^{-9}~J$

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3 years ago

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2 years ago