Forget about the car's speed.  You don't need it.
The tires spin 840 rpm.  That's 840 <em>Revolutions per Minute</em> . 
There are 60 seconds in 1 minute.  So something that happens 840 times in 1 minute happens (840 / 60) times every second.
(840 rev per minute) / (60)  =  <em>14 revs per second</em> .
 
        
             
        
        
        
The greater the energy, the larger the frequency and the shorter (smaller) the wavelength. Given the relationship between wavelength and frequency — the higher the frequency, the shorter the wavelength — it follows that short wavelengths are more energetic than long wavelengths.
        
             
        
        
        
Answer:
F=1.4384×10⁻¹⁹N
Explanation:
Given Data
Charge q= -8.00×10⁻¹⁷C
Distance r=2.00 cm=0.02 m
To find 
Electrostatic force
Solution
The electrostatic force between between them can be calculated from Coulombs law as

Substitute the given values we get

 
        
             
        
        
        
A star's temperature is most likely indicated by the color of it. The hotter the star, the bluer it is. The colder the star, the redder it is. 
        
             
        
        
        
Answer:
C) 24.4°
Explanation:
let nd = 2.419 be the index of refraction of diamond and na  = 1.0 be the index of refraction of air  and ∅c be the critical angle.
according to Snell's Law:
sin(∅c) = na/nd
sin(∅c) = (1.0)/(2.419)
       ∅c = 24.4°