Answer:
-75 cm
Explanation:
At l ; F = 350 Hz
At l + 15 cm ; F = 280 Hz
I = 350
I + 15 = 280
280I = 350(I + 15)
280I = 350I + 5250
280I - 350I = 5250
-70I = 5250
I = - 75cm
The length is - 75 cm
I agree the best choice is A............
Answer:

Explanation:
Mass of a hockey puck, m = 0.17 kg
Force exerted by the hockey puck, F' = 35 N
The force of friction, f = 2.7 N
We need to find the acceleration of the hockey puck.
Net force, F=F'-f
F=35-2.7
F=32.3 N
Now, using second law of motion,
F = ma
a is the acceleration of the hockey puck

So, the acceleration of the hockey puck is
.
<span>You are given two cars, one in front of the other, that are traveling down the highway at 25 m/s. You are also given a frequency of 500 Hz of the car travelling behind it. You are asked what is the frequency heard by the driver of the lead car. This problem can be solved using the Doppler effect
sound frequency heard by the lead car = [(speed of sound + lead car velocity)/( speed of sound + behind car velocity)] * (sound of frequency of the behind car)
</span>sound frequency heard by the lead car = [(340 m/s + 25 m/s)/(340 m/s - 25 m/s)] * (500 Hz)
sound frequency heard by the lead car = 579 Hz
Answer:
The velocity will be v1 = 0.58[m/s]
Explanation:
This problem can be solved by the law of conservation of the moment, which explains that the moment of a system remains constant because there are no external forces acting on it.
We have the following initial data:
m1 = mass of the skater = 55 [kg]
m2 = mass of the ball = 3 [kg]
v2 = velocity of the ball = 8 [m/s]
Therefore:
![m_{1}*v_{1}+m_{2}*v_{2}=m_{1}*v_{1}+m_{2}*v_{2}\\(50*0)+(3*0)=(50*v_{1})+(3*8)\\50+3-24=50*v_{1}\\v_{1}= 0.58[m/s]](https://tex.z-dn.net/?f=m_%7B1%7D%2Av_%7B1%7D%2Bm_%7B2%7D%2Av_%7B2%7D%3Dm_%7B1%7D%2Av_%7B1%7D%2Bm_%7B2%7D%2Av_%7B2%7D%5C%5C%2850%2A0%29%2B%283%2A0%29%3D%2850%2Av_%7B1%7D%29%2B%283%2A8%29%5C%5C50%2B3-24%3D50%2Av_%7B1%7D%5C%5Cv_%7B1%7D%3D%200.58%5Bm%2Fs%5D)