<span>The key equation is going to come from Mr Planck: E=h \nu
Where h is Plancks constant; and ν is the frequency. This equation gives you the energy per photon at a given frequency. Alas, you're given wavelength, but that's easy enough to convert to frequency given the following equation:
c= lambda / nu
where c is the speed of light; λ (lambda) is the wavelength; and ν is again frequency. As soon as you know the energy of a photon with a wavelength of 550nm, you should know how many photons you would require to accumulate 10^-18J. Be careful with your units.</span>
Answer:
So the acceleration of the child will be 
Explanation:
We have given angular speed of the child 
Radius r = 4.65 m
Angular acceleration 
We know that linear velocity is given by 
We know that radial acceleration is given by 
Tangential acceleration is given by

So total acceleration will be 
<u>Answer</u>
27.7
<u>Explanation</u>
The ball was hit at an angle of 30°, with the horizontal at a speed of 10 m/s. We have to find the horizontal component of speed.
cosx = adjacent/hypotenuse
cos 30 = adjacent / 10
adjacent = 10 cos30
= 8.66 m/s ⇒ This is the horizontal speed.
Now find the horizontal distance.
Distance = speed × time
= 8.66 × 3.2
= 27.71
Answer to the nearest tenth = 27.7
b) intervalul de timp t3 in care prin fata sa trece vagonul urmator
Sper că am ajutat!