D. A magnetic field created by the electric current causes the compass needle to move.
Velocity is height , speed is an object being propelled by force
Send wave from your location to the object and wait until echo is back.
Measure the time taken.
If you know the speed of wave (say sound wave), than just multiply by half time taken wave to return
Answer:
137200000 watts or 137200 kilowatts
Explanation:
The formula for power is P= dhrg
Where P = Power in watts
d = density of water (1000 kg/m^3)
h = height in meters
r = flow rate in cubic meters per second,
g = acceleration due to gravity of 9.8 m/s^2,
Plugging in the known values,
we get
P = 1000 kg/m^3 * 80 m * 175 m^3/s * 9.8 m/s^2
P = 80000 kg/m^2 * 175 m^3/s * 9.8 m/s^2
P = 14000000 kg m/s * 9.8 m/s^2
P = 137200000 kg m^2/s^3
P = 137200000 watts or 137200 kilowatts
The above figure assumes 100% efficiency which is impossible. A good efficiency would be 90% so the actual power available would be close to 0.90 * 137200 = 123480 kilowatts
To solve this problem it is necessary to apply the concepts related to the conservation of the Momentum describing the inelastic collision of two bodies. By definition the collision between the two bodies is given as:

Where,
= Mass of each object
= Initial Velocity of Each object
= Final Velocity
Our values are given as




Replacing we have that



Therefore the the velocity of the 3220 kg car before the collision was 0.8224m/s