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WITCHER [35]
3 years ago
13

If the kinetic energy of the 40kg box is 784 J, what is the velocity before it strikes the ground?

Physics
1 answer:
mamaluj [8]3 years ago
4 0

Answer:

Explanation:

KE=\frac{1}{2}mv^2

784=\frac{1}{2}(40)v^2

784=20v^2

39.2=v^2

v=6.26m/s

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A block is sent up a frictionless ramp along which an x axis extends upward. The figure below gives the kinetic energy of the bl
ss7ja [257]
Kinetic energy =1/2 mv^2 

<span>m=2ke/v^2 </span>

<span>m=2(34)/3.6^2 </span>

<span>m=5.24 </span>

<span>force normal = mg </span>
<span>=5.24 x 9.8 </span>
<span>force normal = 51.4N

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions here.


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3 years ago
Which of the following is an example of an irregular meter? A. Four beats per measure B. Five beats per measure C. Two beats per
Komok [63]
B. 5 beats per measure.
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Need help identifying the rest of the elements!
gregori [183]
I think that number five is lithium
6 0
2 years ago
If a transmission line in a cold climate collects ice, the increased diameter tends to cause vortex formation in a passing wind.
AleksAgata [21]

Answer:

a) f_1=5.587Hz

b) f_{n+1}-f_n=5.587Hz

Explanation:

The frequency of the n^{th} harmonic of a vibrating string of length <em>L, </em>linear density \mu under a tension <em>T</em> is given by the formula:

f_n=\frac{n}{2L} \sqrt{\frac{T}{\mu}

a) So for the <em>fundamental mode</em> (n=1) we have, substituting our values:

f_1=\frac{1}{2(347m)} \sqrt{\frac{65.4\times10^6N}{4.35kg/m}}=5.587Hz

b) The <em>frequency difference</em> between successive modes is the fundamental frequency, since:

f_{n+1}-f_n=\frac{n+1}{2L} \sqrt{\frac{T}{\mu}}-\frac{n}{2L} \sqrt{\frac{T}{\mu}}=(n+1-n)\frac{1}{2L} \sqrt{\frac{T}{\mu}}=\frac{n}{2L} \sqrt{\frac{T}{\mu}}=f_1=5.587Hz

3 0
3 years ago
Radar is used to determine distances to various objects by measuring the round-trip time for an echo from the object. (a) How fa
zloy xaker [14]

Answer:

150000000000 m

0.0000005 seconds

33.33 ns

Explanation:

Speed of electromagnetic waves through vacuum = 3\times 10^8\ m/s

Echo time = 1000 seconds

Echo time is the time taken to reach the object and come back to the observer

Distance = Speed×Time

Distance=3\times 10^8\times \frac{1000}{2}=150000000000\ m

Venus is 150000000000 m away from Earth

Time = Distance / Speed

Time=\frac{75}{3\times 10^8}=0.00000025\ seconds

Echo time will be twice the time

Echo\ time=2\times 0.00000025=0.0000005\ seconds

The echo time will be 0.0000005 seconds

Difference in time = Difference in distance / Speed

\Delta t=\frac{\Delta d}{v}\\\Rightarrow \Delta t=\frac{10}{3\times 10^8}\\\Rightarrow \Delta=33.33\ ns

The accuracy by which I will be able to measure the echo time is 33.33 ns

5 0
3 years ago
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