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3 years ago

Kelly sits on a rock. Her weight is an action force. What is the reaction force?

1 answer:

4 0

The force ffrom the ground that holds the rock up and prevents her from falling through the gound, unless the ground breaks.

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A ball is dropped from the top of the building.it initially moves at 4.0 m/s after 0.5 seconds it moves at 3.8m/s what force is

Ivahew [28]

The correct answer is

Air resistance

In fact, when a ball is in free fall, there are two forces acting on it:

- its weight (force of gravity), acting downward

- the air resistance, acting upward

The effect of the weight is to accelerate the ball, because its direction is the same as the direction of motion of the ball, while the effect of the air resistance is to slow down the ball, because its direction is opposite to that of the motion.

6 0

3 years ago

What to do if vehicle struck by lightning

agasfer [191]

Lighting flows around the outside of a truck, and the majority of the current flows from the cars metal cage into the ground below. It's not very safe to be in a car or truck during bad weather.

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3 years ago

Which is an example of someone responding from a personal perspective?

Anika [276]

Answer:

Explanation:

If Ami is saying she likes it then it it personal. If you are speaking from statistics and studies it is impersonal and technically not from there perspective. All of these do this except C.

5 0

2 years ago

Read 2 more answers

An open pipe of length 0.58 m vibrates in the third harmonic with a frequency of 939Hz. What is the speed of sound through the a

vaieri [72.5K]

363 m/s is the speed of sound through the air in the pipe.

Answer: Option B

<u>Explanation:</u>

The formula used to calculate the wavelength given as below,

$Wavelength (\lambda)=\frac{\text { wave velocity }(v)}{\text { frequency }(f)}$

$v=\lambda \times f$ --------> eq. 1

In power system, harmonics define by positive integers of the fundamental frequency. So the third order harmonic is a multiple of the third fundamental frequency. Each harmonic creates an additional node and an opposite node, as well as an additional half wave within the string.

If the number of waves in the circuit is known, the comparison between standing wavelength and circuit length can be calculated algebraically. The general expression for this given as,

$L=\frac{n \lambda}{2}$

For first harmonic, n =1

$L=\frac{\lambda}{2}$

For second harmonic, n =2

$L=\frac{2 \lambda}{2}=\lambda$

For third harmonic, n =3

$L=\frac{3 \lambda}{2}$

$\lambda=\frac{2 L}{3}$ -------> eq. 2

Here given f = 939 Hz, L = 0.58 m...And, substitute eq 2 in eq 1 and values, we get

$v=\frac{2 \times 0.58 \times 989}{3}=\frac{1089.24}{3}=363.08 \mathrm{m} / \mathrm{s}$

3 0

3 years ago

What process primes a molecule to change in a way that increases its activity, produces motion, or does work

kirza4 [7]

Answer:

cellular respiration.

explanation: cellular respiration, the process by which organisms combine oxygen with foodstuff molecules, diverting the chemical energy in these substances into life-sustaining activities and discarding, as waste products, carbon dioxide and water.

4 0

2 years ago