Answer:
Explanation:
Given dish width= 48ft
Depth = 4ft
Using equation of a parabola
x²= 4py
48² = 4p 4
4p = 576
P= 144ft
Thus the the receiver should be placed 144ft from t the vertex
Answer:
2.295 eV
Explanation:
maximum wavelength, λ = 542 nm = 542 x 10^-9 m
The work function of the metal is defined as the minimum amount of energy falling on the metal so that the photo electrons just ejects the surface of metal.

where, h is the Plank's constant and c be the speed of light
h = 6.634 x 10^-34 Js
c = 3 x 10^8 m/s


Wo = 2.295 eV
Thus, the work function of this metal is 2.295 eV.
Answer: a. 198.6J b. - 198.6J
Explanation: Parameters given:
m = 15kg
g = 9.8m/s²
∅ = 12°
a. Work done by the force Fp on the cart if the ramp is 6.5m long.
Given the formula, Fp = Mgsin∅ = 15 x 9.8 x sin12° = 30.56N
Therefore Work done (Wp) = Fp x Ramp Length = 30.56 x 6.5 = 198.64Nm or 198.6J
b. The work done by the force mg on the cart.
Since the cart is being pushed upwards, it acts against gravity with its direction of motion. Taking into account the formula from the previous answer for Work Done (Wg) = Fmg x distance
= 15kg x -9.8m/s² x Sin12° x 6.5m
= - 198.6J
Answer:
a.96cm
b.77cm
Explanation:
Highest intensity,
=19cm
Lowest intensity,
=29cm
48cm is the distance for half-wave, wavelength =48cm*2=96cm
b. From a, above we know that half-wavelength is 48cm
Also, the distance of known maximum is 29cm
Next maximum is calculated as:

The next maximum will occur at 77cm