Answer:
Speed of the approaching train = 15.45 m/s
Explanation:
Given:
Frequency F0 = 220 Hz
Beat frequency F1 = 10.0 Hz
Find:
Speed of the approaching train
Computation:
Approaching frequency F2 = 220 + 10.0 Hz
Approaching frequency F2 = 230 Hz
Doppler shift;
F = [(v+v0)/(v-vS)]F0
230 = [(340+v0)/(340-0)]220
V0 = 15.45 m/s
Speed of the approaching train = 15.45 m/s
Answer:
The electromotive force is the voltage measured across the cell terminals when "NO" current is being drawn. That is why electromotive forces are used in Wheatstone Bridges which measure the resistance of an external object.
Just measuring the voltage across a cell does not give one the true EMF because current drawn from the cell will cause a reduction of voltage of I * R where R is the internal resistance of the cell.
Answer:
(a) Waves P and Q have the same wavelength but wave P has twice the amplitude of wave Q.
(b) Waves Q and R have the same amplitude but wave R has twice the wavelength of wave Q.
(c) Wave T shows a steady frequency but changing amplitude.
(d) Wave S shows steady amplitude but a changing frequency.
e) Waves Q and R have a low amplitude and a steady frequency.
C. Your feet push down on the ground, and the ground pushes up on your feet.
Answer:
<em>The arrangement with the greatest resistance is the light bulb of option C. 4 W, 4.5 V</em>
Explanation:
The equation for electric power is
power P = IV
also, I = V/R,
substituting into the equation, we have
a) 
= 2.8 Ω
b) 
= 1.5 Ω
c) 
5.06 Ω
d) 
= 4.5 Ω
from the calculations, one can see that the lightbulb with te greates resistance is
<em>C. 4 W, 4.5 V</em>
