<u>Answer</u>
8. 2 Hz
9. 0.5 seconds
10. 20 cm
<u>Explanation</u>
<u>Q 8</u>
Frequency is the number of oscillation in a unit time. It is the rate at which something repeats itself in a second.
In this case, the spring bob up and down 2 times per second.
∴ Frequency = 2 Hz
<u>Q 9</u>
Period is the time taken to complete one oscillation.
2 oscillations takes 1 second
1 oscillation = 1/2 seconds.
∴ Period = 0.5 seconds
<u>Q 10</u>
Amplitude is the the maximum displacement of the spring.
In this case the spring bob up 20 cm. This is it's displacement.
∴ Amplitude = 20 cm
Answer:
The pressure is constant, and it is P = 150kpa.
the specific volumes are:
initial = 0.062 m^3/kg
final = 0.027 m^3/kg.
Then, the specific work can be written as:
![W = \int\limits^{vf}_{vi} {Pdv} \, = P(vf - vi) = 150kPa*(0.0027 - 0.062)m^3/kg = -5.25 kPa*m^3/kg.](https://tex.z-dn.net/?f=W%20%3D%20%5Cint%5Climits%5E%7Bvf%7D_%7Bvi%7D%20%7BPdv%7D%20%5C%2C%20%3D%20P%28vf%20-%20vi%29%20%3D%20150kPa%2A%280.0027%20-%200.062%29m%5E3%2Fkg%20%3D%20-5.25%20kPa%2Am%5E3%2Fkg.)
The fact that the work is negative, means that we need to apply work to the air in order to compress it.
Now, to write it in more common units we have that:
1 kPa*m^3 = 1000J.
-5.25 kPa*m^3/kg = -5250 J/kg.
When it has a magnetic field
Just do energy spent divided by time to get your answer. With this we can say a human might be able to!
Answer:
Explanation:
As we know that the ball is projected upwards so that it will reach to maximum height of 16 m
so we have
![v_f^2 - v_i^2 = 2 a d](https://tex.z-dn.net/?f=v_f%5E2%20-%20v_i%5E2%20%3D%202%20a%20d)
here we know that
![v_f = 0](https://tex.z-dn.net/?f=v_f%20%3D%200)
also we have
![a = -9.81 m/s^2](https://tex.z-dn.net/?f=a%20%3D%20-9.81%20m%2Fs%5E2)
so we have
![0 - v_i^2 = 2(-9.81)(16)](https://tex.z-dn.net/?f=0%20-%20v_i%5E2%20%3D%202%28-9.81%29%2816%29)
![v_i = 17.72 m/s](https://tex.z-dn.net/?f=v_i%20%3D%2017.72%20m%2Fs)
Now we need to find the height where its speed becomes half of initial value
so we have
![v_f = 0.5 v_i](https://tex.z-dn.net/?f=v_f%20%3D%200.5%20v_i)
now we have
![v_f^2 - v_i^2 = 2 a d](https://tex.z-dn.net/?f=v_f%5E2%20-%20v_i%5E2%20%3D%202%20a%20d)
![(0.5v_i)^2 - v_i^2 = 2(-9.81)h](https://tex.z-dn.net/?f=%280.5v_i%29%5E2%20-%20v_i%5E2%20%3D%202%28-9.81%29h)
![-0.75v_i^2 = -19.62 h](https://tex.z-dn.net/?f=-0.75v_i%5E2%20%3D%20-19.62%20h)
![0.75(17.72)^2 = 19.62 h](https://tex.z-dn.net/?f=0.75%2817.72%29%5E2%20%3D%2019.62%20h)
![h = 12 m](https://tex.z-dn.net/?f=h%20%3D%2012%20m)