'Suppose your hand moves upward by 0.50m while you are throwing the ball. The ball leaves your hand with an upward velocity of 2
0.0 m/s. Find the magnitude of the force (assumed constant) that your hand exerts on the ball. Ignore air resistance.' Now my question is not 'What is the magnitude' but rather: why did I get (roughly) the same answer using F=ma when you were supposed to use the total mechanical energy (W+K1+U1=K2+U2). So I'm more confused about how the 2 formulas are 'related', what the force actually represents in both, when to use what and if there is an actual difference.
1 answer:
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The maximum speed of the object under simple harmonic motion is 0.786 m/s.
The given parameters:
- Position of the particle, y = 0.5m sin(πt/2)
y = A sin(ωt + Ф)
where;
- A is the amplitude = 0.5 m
- ω is the angular speed = π/2
The maximum speed of the object is calculated as follows;
Thus, the maximum speed of the object under simple harmonic motion is 0.786 m/s.
Learn more about simple harmonic motion here: brainly.com/question/17315536
Answer:
a) f' = 432 Hz
b) I = 8.12*10^-4 W/m^2
Explanation:
a) To calculate the frequency of sound waves that car receives, you take into account the Doppler effect. In this case (observer moves away of the source) you have the following formula:
(1)
where
f: frequency of the source = ?
v: speed of sound = 343 m/s
vo: speed of the observer = 40.0 m/s
vs: speed of the source = 0 m/s (stationary)
You replace the values of all parameters in the equation (1):
To calculate f' you first calculate the frequency of the sound wave, by using the following formula:
v: speed of sound
λ: wavelength = 0.700 m
Next, you replace the values of all parameters in the equation (1):
hence, the frequency perceived by the car is 432 Hz
b) To calculate the power of the sound wave, when the car is 70.0 maway from the speaker, you use the following formula:
P: power of the source = 50.0 W
r: distance to the source = 70.0 m
hence, the intensity is 8.12*10^⁻4 W/m^2