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3 years ago

A rock is dropped from rest. How fast is it going after it has been falling for 9.2 s?

Physics

1 answer:

natka813 [3]3 years ago

6 0

90.2 m/s. A rock dropped from rest after it has falling for 9.2 seconds will have a velocity of 90.2m/s.

The bodies left in free fall increase their speed (downwards) by 9.8 m/s² every second. The acceleration of gravity is the same for all objects and is independent of the masses of these. In the free fall the air resistance is not taken into account.

v = g*t

v = (9.8m/s²)(9.2s) = 90.2 m/s

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2 years ago

two charges having the same charge magnitude experiencing an attracting force of 3.60N when the charges are 30cm apart.what is t

Tomtit [17]

The charges have opposite sign and magnitude $6 \mu C$

Explanation:

The magnitude of the electrostatic force between two electric charges is given by Coulomb's law:

$F=k\frac{q_1 q_2}{r^2}$

where:

$k=8.99\cdot 10^9 Nm^{-2}C^{-2}$ is the Coulomb's constant

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r is the separation between the two charges

In this problem, we have:

F = 3.60 N is the force between the two charges

r = 30 cm = 0.30 m is their separation

The two charges have same magnitude, so

$q_1 = q_2 = q$

So we can rewrite the equation as

$F=\frac{kq^2}{r^2}$

And solving for q:

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Moreover, the force between the charges is attractive: we know that charges of same sign repel each other while charges of opposite sign attract each other, therefore the charges in this problem have opposite sign, so

$q_1 = 6 \mu C\\q_2 = -6 \mu C$

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2 years ago

A sound wave has frequency 620 Hz and wavelength 10.5 m. What is the speed of sound waves?

olasank [31]

Answer:

Explanation:

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2 years ago

What is the Sl unit for speed

Akimi4 [234]

Answer: meter per second

Explanation: meter per second

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3 years ago

A small piece of Styrofoam packing material is dropped from a height of 2.60 m above the ground. Until it reaches terminal speed

Vadim26 [7]

Answer:

Explanation:

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a = g at t = 0

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a = g - 22.25 x .15

= 9.8 - 3.31

= 6.5 m /s²

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3 years ago