Answer:
a). 6 seconds
b). 12 seconds
c). 176.4 meters
Explanation:
a). Equation to be applied to calculate the time taken by the rocket to reach at the peak height,
v = u - gt
where v = final velocity
u = initial velocity = 58.8 m per sec
g = gravitational pull = 9.8 m per sec²
t = duration of the flight
At the peak height,
v = 0
Therefore, 0 = 58.8 - (9.8)(t)
t = 
= 6 seconds
b). Total time of flight = 2(Time taken to go up)
= 2×6
= 12 sec
c). Formula to get the peak height is,

h = (58.8)6 - 
= 352.8 - 176.4
= 176.4 meters
Answer:
The correct option is;
- 4x
Explanation:
From the inverse square law, as the distance from the source of a physical quantity increases, the intensity of the source is spread over an area proportional to the square of the distance of the object from the source
The inverse square law can be presented as follows;

As the distance, r, increases, the surface it covers also increases by the power of 2
Therefore, where the distance increases from r to 2·r, we have;
When, I, remain constant

The surface increases to 4·S by the inverse square law
Therefore, the correct option is 4 × x.
Answer:
<em>6.02 dB increase </em>
<em></em>
Explanation:
Let us take the initial power from the speaker P' = P Watt
then, the final power P = 4P Watt
for a given unit area, initial intensity (power per unit area) will be
I' = P Watt/m^2
and the final quadrupled sound will produce a sound intensity of
I = 4P Watt/m^2
Increase in loudness is gotten from the relation
ΔL =
where
I = final sound intensity
I' = initial sound intensity
imputing values of the intensity into the equation, we have
==>
=
= <em>6.02 dB increase </em>
Answer:
18000 Bg
Explanation:
after 15 minutes = 36000/2
After 30 minutes = 36000/4
30 minutes × 2 = 1 hour
After 1 hour = 36000/4 × 2 = 18000 Bg
Answer:

Explanation:
It is given that,
Area of cross section of the pipe, 
Area of cross section of the another pipe, 
Speed of water in first pipe, 
To find,
Speed of the water flowing in the second pipe.
Solve,
Let
is the speed of water flowing in the second pipe. The relation between the area of cross section and the velocity is given by the continuity equation. It is given by :




Therefore, the water is flowing in the second pipe at the rate of 8 m/s.