Answer:
f'=5.58kHz
Explanation:
This is an example of the Doppler effect, the formula is:

Where f is the actual frequency,
is the observed frequency,
is the velocity of the sound waves,
the velocity of the observer (which is negative if the observer is moving away from the source) and
the velocity of the source (which is negative if is moving towards the observer). For this problem:


Vi = 15 m/s
t = 2 s
a = 9.8 m/s^2
y = ?
The kinematic equation that has all of our variables is d = Vi*t + 0.5*a*t^2
y = 15*2 + 0.5*9.8*2^2 = 49.6 m
Answer:
1) v = 0.45 m/s
2) v = 0.65 m/s
3) v = 0.75 m/s
Explanation:
1) We can find the speed of the object by conservation of energy:


Where:
k: is the spring constant = 280 N/m
v: is the speed of the object =?
m: is the mass of the object = 5.00 kg
x: is the displacement of the spring

2) When the object is 5.00 cm (0.050 m) from equilibrium, the speed of the object is:
3) When the object is at the equilibrium position, the speed of the object is:

I hope it helps you!
Answer: velocity
Explanation: Hope this helps :)