Answer:
![v_x = 1.26 m/s](https://tex.z-dn.net/?f=v_x%20%3D%201.26%20m%2Fs)
Explanation:
given,
weight of swimmer = 510 N
length of ledge, L = 1.75 m
vertical height of the cliff, h = 9 m
speed of the swimmer = ?
horizontal velocity of the swimmer should be that much it can cross the wedge.
distance = speed x time
d = v_x × t
1.75 = v_x × t ........(1)
now,time taken by the swimmer to cover 9 m
initial vertical velocity of the swimmer is zero.
using equation of motion for time calculation
![s = ut +\dfrac{1}{2}gt^2](https://tex.z-dn.net/?f=s%20%3D%20ut%20%2B%5Cdfrac%7B1%7D%7B2%7Dgt%5E2)
![9= 0+\dfrac{1}{2}\times 9.8\times t^2](https://tex.z-dn.net/?f=9%3D%200%2B%5Cdfrac%7B1%7D%7B2%7D%5Ctimes%209.8%5Ctimes%20t%5E2)
t² = 1.938
t = 1.39 s
same time will be taken to cover horizontal distance.
now, from equation 1
1.75 = v_x × 1.39
![v_x = 1.26 m/s](https://tex.z-dn.net/?f=v_x%20%3D%201.26%20m%2Fs)
horizontal speed of the swimmer is equal to 1.26 m/s
Whenever lightning strikes it separates the air where it goes. This air then rushes back together making a loud noise when it connects, creating thunder.
Answer:
This difference is kept to a minimum because the resistance in transformers is a few tens of ohms and the resistance of modern voltmeters is of the order of MΩ.
Explanation:
A voltmeter is built by a galvanometer and a resistance in series, this set is connected in parallel to the resistance where the voltage is to be measured, therefore the voltage is divided between the voltmeter and the element to be measured, consequently the measured voltage It is less than the calculated one, since for them the resistance of the voltmeter is assumed infinite.
This difference is kept to a minimum because the resistance in transformers is a few tens of ohms and the resistance of modern voltmeters is of the order of MΩ.
Anything times zero is zero