Answer:
The time it takes the ball to rise equals the time it takes to fall.
Explanation:
because what goes up at some point must come down
Answer:
D
Explanation:
F = G m1 m2 / r^2 now double r
F = G m1m1/ (2r)^2
F = 1/4 G m1m2/r^2 <===== this is 1/4 of the original
Answer:
c. is negative
Explanation:
When the magnitude of force is multiplied with the force vector's projection along the direction of the vector of displacement which is negative as it is a resistive force we get the work done.
As the wind is acting in opposite direction of the force which is being applied by the plane the work done will be negative. Also, the net work will be the sum of many smaller negative quantities.
Hence, the answer here is negative.
There are two units of sound: intensity and in decibels. Decibels are not additive, you must convert it first to units of intensity (W/m²) using this formula:
dB = 10 log(I/10⁻¹²)
A. 100 dB = 10 log(I/10⁻¹²)
Solving for I,
I = 0.01 W/m²
90 dB = 10 log(I/10⁻¹²)
Solving for I,
I = 0.001
Ratio = 0.01/0.001 = 10
<em>Thus,the choir is 10 times more intense than the soloist.</em>
B. Since there are 90 singers, there would be 9 groups of 10-person choir that produces 100 dB or 0.01 W/m². The total intensity would be
Total intensity = 0.01 W/m² (original choir) + 0.001 W/m² (soloist) + 10(0.01 W/m²) (additional 90 singers) = 0.111 W/m²
dB = 10 log(0.111/10⁻¹²) = <em>110.45 dB</em>
C. Rock concert:
120 dB = 10 log(I/10⁻¹²)
Solving for I,
I = 1 W/m²
Ratio = 1/0.111 = 9
<em>Therefore, the rock concert is 9 times more intense than the choir concert.</em>
