Here we have to calculate the number of rotations made by earth around its own axis in the entire life time of a human being.
The average human life is 50 years .
Each year is 365.5 days
Hence 
=18,275 days
The earth rotates around its own axis in 23 hours 56 minutes and 4 second which is approximately equal to 24 hours or one days.
Hence one rotation takes one days.
⇒18,275 days =18,275 rotations
Hence the total number of rotations made by earth around its own axis in the life time of a average human life time will be 18,275 times
Answer:
b) d = 0.71 Km
Explanation:
Car kinematics
Car 1 moves with uniformly accelerated movement
Formula (1)
d: displacement in meters (m)
v₀: initial speed in m/s
vf: final speed in m/s
a: acceleration in m/s²
Equivalences:
1mile = 1609.34 meters
1 hour = 3600s
1km = 1000m
Known data


a = -0.5 m/s²
Distance calculation
We replace data in the Formula (1)




It would be b. anemometer. it measures the speed of wind or any current of gas.
<span>Wavelength = (speed) / (frequency)
Speed of EM radiation = 3 x 10⁸ m/s
Frequency (3 × 10¹⁹ Hz) ===> wavelength = 0.01 nanometer
Frequency (3 × 10¹⁶ Hz) ===> wavelength = 10 nanometers</span>
This is the region of X-rays.
The proper time would be the time measured in the rest frame of the event, so in this case the observer on mars would measure the proper time.