Answer:
fundamental formula for density = Kg/m³
Explanation:
density = mass/volume
To solve this problem we will apply the concepts related to the Doppler Effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other.
Mathematically it can be described as

Where,
v = Speed of sound
f' = Reflected frequency
f = Emitted Frequency
= Speed of the object
Assuming that the speed of the medium is the speed of sound of 343m / s, we will then have that:


Answer:
Air resistance have some significant role in projectile motion if the motion lasts for some time.
Explanation:
- Air resistance or air drag seems to be important in daily actvities and games like baseball.
- The trajectory of the projectile with or without air resistance or air drag is totally different.
- When we neglect air drag, the only acting force is gravity against the motion so the maximum height and range are suppose Hmax and R.
- Now, when we consider air drag, it is important to notice that there are two forces against the motion of the ball and along the direction of gravity. It seems that both maximum height and range are lesser Hmax'< Hmax and R'<R.