We have to calculate how many square feet a school custodian has to wax and to choose the correct answer. A gymnasium floor is in the shape of the square ( 20 by 20 feet ). The area of the square is : A = L^2. For L = 20 ft, A = 20^2 = 20 * 20 = 400 ft^2. Answer: <span>D. 400 square feet.</span>
Answer:
the charge of the particle is 2.47 x 10⁻¹⁹ C
Explanation:
Given;
mass of the particle, m = 6.64 x 10⁻²⁷ kg
velocity of the particle, v = 8.7 x 10⁵ m/s
strength of the magnetic field, B = 1.3 T
radius of the circle, r = 18 mm = 1.8 x 10⁻³ m
The magnetic force experienced by the charge is calculated as;
F = ma = qvB
where;
q is the charge of the particle
a is the acceleration of the charge in the circular path

Therefore, the charge of the particle is 2.47 x 10⁻¹⁹ C
Brian’s Complexity Brian’s Complexity Brian’s Complexity Brian’s Complexity
Answer:
E = 3.54 x 10⁻¹⁹ J
Explanation:
The energy of the photon can be given in terms of its wavelength by the use of the following formula:

where,
E = energy = ?
h = Plank's Constant = 6.626 x 10⁻³⁴ Js
c = speed of light = 2.998 x 10⁸ m/s
λ = wavelength of light = 560.6 nm = 5.606 x 10⁻⁷ m
Therefore,

<u>E = 3.54 x 10⁻¹⁹ J</u>