<span>At an instant when the displacement is equal to a/2,
Potential energy U = 1/2ka(square) where a is displacement.
when a= a/2
U = 1/4ka(square)
U = E/4
Potential Energy = 1/4 Total energy</span>
Answer:
a) The car was moving at a speed of 
b) The negative sign of 
denotes that the observer is coming towards the police car which is the source of the sound.
c) 
Explanation:
Given:
- original frequency of the source,
- speed of the source,
- velocity of the obstacle car be,
- speed of sound,
- observed frequency,
<u>Using the equation from the Doppler's effect:</u>
a)
The car was moving at a speed of
b)
The negative sign of denotes that the observer is coming towards the police car which is the source of the sound.
c)
Now when, 
Then, 
Using the Doppler's eq.:
Where is the rest of the sentence?
What What What What...... error
Answer:
in pulley there are different kinds.but the most common one are fixed,moveable and compound pulley. in this question we asked about movable pulley.
Explanation:
Given request solutions
L=500N a,M.A=? a,M.A=L/E =5/3
E=300N b,V.R=? b,V.R=2
c,efficiency =? c,£=M.A/V.R=5/6
£=IS NOT THE REAL SYMBOLS OF EFFICIENCY BUT I IS LOOK LIKE THIS
I THINK I HELPED
