Answer:
D. 4000 km
Explanation:
f = Frequency of wave that is being transmitted = 76 Hz
= Wavelength of wave that is being transmitted
v = The velocity of electromagnetic waves through air = 
Velocity of a wave is given by

Hence, the approximate wavelength of the waves is 4000 km
Speed of wave = Frequency x Wavelength
so Speed = 0.7 x 9 = 6.3
remember the calculations must be done in their Basic SI units.
therefore, you have to convert 7 mm to meters which becomes 0.7 meters
Answer:
The spring was compressed the following amount:

Explanation:
Use conservation of energy between initial and final state, considering that the surface id frictionless, and there is no loss in thermal energy due to friction. the total initial energy is the potential energy of the compressed spring (by an amount
), and the total final energy is the addition of the kinetic energies of both masses:



Answer:
3050.6 Litre .
Explanation:
Total time of heart beat = Total time of race = 2 hrs , 39 minutes and 54 seconds
= 2 x 60 + 39 + 54/60 min
= 120 + 39 + .9 min
= 159.9 min
rate of heart beat = 170 per min
Total no of heart beat during race = 170 x 159.9
volume of blood per kg per beat = 2.5 mL per kg of weight
body weight = 99 pounds = .4535 x 99 kg = 44.89 kg
volume of blood per beat = 2.5 mL x 44.89 mL
= 112.225 mL .
Total required volume of blood = 112.225 x 170 x 159.9 mL
= 3050612 mL
= 3050.6 L.
No, personal trainers and doctors have very different careers. Though they both do well for the body and health.