Answer: 0.392 m/s
Explanation:
The Doppler shift equation is:

Where:
is the actual frequency of the sound wave
is the "observed" frequency
is the speed of sound
is the velocity of the observer, which is stationary
is the velocity of the source, which are the red blood cells
Isolating
:


Finally:

Answer:
11.47 m high
Explanation:
All of the Kinetic Energy converts to Potential energy
1/2 m v^2 = mgh divide both sides by 'm'
1/2 v^2 = gh (note that the masses given are irrelevant !)
(1/2 v^2) / g = h
(1/2 (15^2) / 9.81 = h = 11.47 m
Answer:
(a) F = 239.575 N (b) t = 0.00649s or 6.49 ms
Explanation:
(a) By law of energy conservation, the bullet kinetic energy will be transferred to work done on stopping it from moving.
Formula for Kinetic Energy
where m is bullet mass, v is the velocity
Formula for work
where F is the average force and S is the distance travelled.



Substitute m = 4.2 g = 0.0042 kg, v = 370 m/s and S = 1.2 (m)

(b) If the force is constant, since the mass is constant and F = ma according to Newton's 2nd law, the acceleration on bullet is also constant

We also have 
At the time the bullet is coming to rest, 
Therefore, 

Answer:

Explanation:
F = Magnetic force = 4.11 N
= Net current
= Current in one of the wires = 7.68 A
B = Magnetic field = 0.59 T
= Angle between current and magnetic field = 
= Length of wires = 2.64 m
= Current in the other wire
Magnetic force is given by

Net current is given by

The current I is
.
Answer: False
Explanation:
The statement that the environment affects people, but people don't affect the environment is incorrect. It should be noted that people also affect the environment.
Some of our impact on the environment include pollution, deforestation, overpopulation, burning of fossil fuels etc. Thus has resulted in changes such as erosion, climate change, etc.