Average velocity = (800+1600)/(4+10)
= 171.42m/s
Acceleration....................................... <span />
<h2>
Answer: an underground lake</h2>
Explanation:
In general, sound (mechanical waves) travels faster in solids than in liquids, and faster in liquids than in gases. This is because <u>the speed of the mechanical waves is determined by a relationship between the elastic properties of the medium </u>in which they are propagated and the mass per unit volume of the medium (that is:<u>density</u>).
In other words: The speed of sound varies depending on the medium through which the sound waves travel.
So, if we are told the sound wave initially had a speed of 4,000 m/s and it suddenly decreases to 1,500 m/s, this means the sound waves passed from a solid medium to a liquid medium.
Hence, the correct option is: an underground lake.
Answer:
The value of resistance when power is 1100 watts = 
= 50 ohms
Explanation:
Power 
= 2200 Watts
Resistance 
= 25 ohms
Power 
= 1100 Watts
Resistance = we have to calculate
Given that the power in an electric circuit varies inversely with the resistance
⇒ P ∝ 
⇒ 
= 
⇒ 
= 
⇒ = 50 ohms
This is the value of resistance when power is 1100 watts.
Potential energy = mgh
= 53.5 x 9.8 x 4.7
= 2464.21 Joules
