Explanation:
Given that,
Frequency of train horn, f = 218 Hz
Speed of train, 
The speed of sound, V = 344 m/s (say)
The speed of the observed person, 
(a) When the train approaches you, the Doppler's effect gives the frequency as follows :

(b) When the train moves away from you, the Doppler's effect gives the frequency as follows :

Hence, this is the required solution.
If we neglect friction/air resistance, then the horizontal component
doesn't change, and the vertical component becomes (9.8 m/s downward)
greater each second thanks to gravity.
So, after 2 seconds, the horizontal component is still 40 m/s, and the
vertical component is (30 - 2·9.8) = 10.4 m/s upward.
Choice #1 says this.
Answer:
Part a)

Part b)

Explanation:
Part a)
Torque on the rod is due to two forces
(i) Due to weight of the rod at mid point
(ii) Due to external force applied at the end
Now we have



Part b)
As per Newton's law we know that

now we have


MRI-Magnetic resonsance imaging
Look at the pic!! Hope
It helps love ❤️
Answer:
I am pretty sure it is B My friend hope you are well
Explanation: