Explanation:
the average velocity of the car is 15 m/s example I have this on a test
Answer:
Pi(3.14) radians or 180º degrees
Explanation:
First of all, we need to obtain the wavelength of a wave traveling to the speed of sound and 420 Hz of frequency.
The formula is:

where l = wavelength in meters
With current values:
l = 336 [m/s]/420[1/s] = 0.8 meters
Since a complete cycle (360º or 2pi radians) needs 0.8 meters to complete, 0.4 meters or 40 cm is just half of it, making a 180º degree phase or 3.14 radians.
Answer:
-1.2 kg - m/s
Explanation:
And we need to find out the change in momentum of the body . Here ,
- velocity before collision (u) = 10m/s
- velocity after collision (v) = 2m/s .
We know that momentum is defined as amount of motion contained in a body . Mathematically ,
Therefore change in momentum will be,
Since the direction of velocity changes after the collision , the velocity will be -2m/s .