To solve this problem we need to apply the corresponding sound intensity measured from the logarithmic scale. Since in the range of intensities that the human ear can detect without pain there are large differences in the number of figures used on a linear scale, it is usual to use a logarithmic scale. The unit most used in the logarithmic scale is the decibel yes described as
Where,
I = Acoustic intensity in linear scale
= Hearing threshold
The value in decibels is 17dB, then
Using properties of logarithms we have,
Therefore the factor that the intensity of the sound was
Answer:
The speed of the 270g cart after the collision is 0.68m/s
Explanation:
Mass of air track cart (m1) = 320g
Initial velocity (u1) = 1.25m/s
Mass of stationary cart (m2) = 270g
Velocity after collision (V) = m1u1/(m1+m2) = 320×1.25/(320+270) = 400/590 = 0.68m/s
<h2>
Answer:</h2>
The rate of deceleration is -0.14
<h2>
Explanation:</h2>
Using one of the equations of motion;
v = u + at
where;
v = final velocity of the boat = 0m/s (since the boat decelerates to a stop)
u = initial velocity of the boat = 25m/s
a = acceleration of the boat
t = time taken for the boat to accelerate/decelerate from u to v = 3 minutes
<em>Convert the time t = 3 minutes to seconds;</em>
=> 3 minutes = 3 x 60 seconds = 180seconds.
<em>Substitute the values of v, u, t into the equation above. We have;</em>
v = u + at
=> 0 = 25 + a(180)
=> 0 = 25 + 180a
<em>Make a the subject of the formula;</em>
=> 180a = 0 - 25
=> 180a = -25
=> a = -25/180
=> a = -0.14
The negative value of a shows that the boat is decelerating.
Therefore, the rate of deceleration of the speed boat is 0.14
Answer:
Explanation:
Kinetic energy= K.E = (1/2) × mv²
K.E = 0.5× 0.8kg× 100m²/s² = 40 N
Answer:
<em>The lighten travels 0.853 miles.</em>
Explanation:
Sound: Sound is a form of wave which is conveyed through an elastic medium from a vibrating body to a listener.
v = 2x/t .......................................... Equation 1
making x the subject of the equation
x = vt/2........................................ Equation 2
Where v = velocity of sound in air, x = distance traveled by the sound, t = time
Given: v = 344 m/s t = 8 s
Substituting into equation 2
x = 344(8)/2
x = 1376 m.
x = 1376×0.00062 miles = 0.853 miles
<em>Thus the lighten travels 0.853 miles.</em>