Answer:


Explanation:

Solve using the quadratic formula.


Your weight pushing down on the chair is the action force. The reaction force is the force exerted by the chair that pushes up on your body.
This means acceleration a is constant.
Let
a) vo be the initial speed, at t=0
b) v be the final speed after time t
c) d distance travelled in time t
Then we have:
a) v=vo+a×t
b) v²=vo²+2×a×d (Galilei's equation)
c) d=vo×t+a×t²/2
d) average speed vm=(vo+v)/2
Given that,
Output power = 87 W
Decibel reading = 120 dB
We need to calculate the intensity of sound
Using formula of intensity of sound

Put the value into the formula





We need to calculate the distance
Using relation of power out[ut and intensity

Put the value into the formula



Hence, The distance is 2.63 m