1200 km to 2 s.f.
If you want to approximate it further then 1000 km.
<span>A)<span>Constructive and destructive interference of sound waves.</span></span>
If committees is an option it is the correct one.
Answer:
A. 1/50π V
Explanation:
Given;
magnetic flux through the coil, φm = (1/50π) cos 100πt
t = 1/200 s
The magnitude of the induced EMF is given by;
![EMF = \frac{d \phi_m}{dt} \\\\EMF =\frac{d}{dt} (1/50 \pi)cos \ 100\pi t)\\\\EMF = (1/50 \pi)cos \ 100\pi \\\\EMF =(1/50 \pi)cos \ 100 *180\\\\ EMF =(1/50 \pi)cos \ 18000\\\\ EMF =(1/50 \pi) (1)\\\\EMF =(1/50 \pi) \ V](https://tex.z-dn.net/?f=EMF%20%3D%20%5Cfrac%7Bd%20%5Cphi_m%7D%7Bdt%7D%20%5C%5C%5C%5CEMF%20%3D%5Cfrac%7Bd%7D%7Bdt%7D%20%281%2F50%20%5Cpi%29cos%20%5C%20100%5Cpi%20t%29%5C%5C%5C%5CEMF%20%3D%20%281%2F50%20%5Cpi%29cos%20%5C%20100%5Cpi%20%5C%5C%5C%5CEMF%20%3D%281%2F50%20%5Cpi%29cos%20%5C%20100%20%2A180%5C%5C%5C%5C%20EMF%20%3D%281%2F50%20%5Cpi%29cos%20%5C%2018000%5C%5C%5C%5C%20EMF%20%3D%281%2F50%20%5Cpi%29%20%281%29%5C%5C%5C%5CEMF%20%3D%281%2F50%20%5Cpi%29%20%5C%20V)
Therefore, the magnitude of the induced EMF is 1/50π V
The correct option is "A. 1/50π V"
Q: A rock is thrown off of a 100 foot cliff with an upward velocity of 45 m/s. As a result its height after t seconds is given by the formula:
h(t)=100+45t−4.9t2
(a)
What is its height after 3 seconds?
(b)What is its velocity after 3 seconds?
Answer:
(a) 190.9 m.
(b) 15.6 m/s upward
Explanation:
Given:
h(t) = 100 + 45t - 4.9t²
The height after 3 seconds,
t = 3 s
Substitute the value of t in to the equation above.
h(3) = 100+45(3)-4.9(3)²
h(3) = 100+135-44.1
h(3) = 190.9 m
Therefore the height after 3 seconds = 190.9 m.
(b) Velocity after 3 seconds
The velocity is obtained by differentiating h(t) with respect to time
v = dh(t)/dt
dh(t)/dt = 45-9.8t
v = 45 - 9.8t ......................................... Equation 1
t = 3 s.
Substitute the value of t into the equation above,
v = 45 - 9.8(3)
v = 45- 29.4
v = 15.6 m/s
Thus the velocity after 3 seconds = 15.6 m/s upward