Answer:
Explanation:
Given
Train travels towards south with a velocity if 
Rain makes an angle of
with vertical
If an observer sees the drop fall perfectly vertical i.e. horizontal component of rain velocity is equal to train velocity
suppose
is the velocity of rain with respect to ground then



Therefore velocity of rain drops is 27.36 m/s
The answer Is B! Good luck
Answer:
a. The station is rotating at 
b. the rotation needed is 
Explanation:
We know that the centripetal acceleration is

where
is the rotational speed and r is the radius. As the centripetal acceleration is feel like an centrifugal acceleration in the rotating frame of reference (be careful, as the rotating frame of reference is <u>NOT INERTIAL,</u> the centrifugal force is a fictitious force, the real force is the centripetal).
<h3>a. </h3>
The rotational speed is :




Knowing that there are
in a revolution and 60 seconds in a minute.


<h3>b. </h3>
The rotational speed needed is :




Knowing that there are
in a revolution and 60 seconds in a minute.


Answer:
If you apply a force to separate 2 opposite poles, the potential energy of the system increases.
Answer:
3000 J
Explanation:
Kinetic energy is:
KE = ½ mv²
If m = 15 kg and v = -20 m/s:
KE = ½ (15 kg) (-20 m/s)²
KE = 3000 J