Answer:
λ = 8.88 x 10⁻⁷ m = 888 nm
Explanation:
The energy band gap is given as:
Energy Gap = E = 1.4 eV
Converting this to Joules (J)
E = (1.4 eV)(1.6 x 10⁻¹⁹ J/1 eV)
E = 2.24 x 10⁻¹⁹ J
The energy required for photovoltaic generation is given as:
E = hc/λ
where,
h = Plank's Constant = 6.63 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of light = ?
Therefore,
2.24 x 10⁻¹⁹ J = (6.63 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/λ
λ = (6.63 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(2.24 x 10⁻¹⁹ J)
<u>λ = 8.88 x 10⁻⁷ m = 888 nm</u>
Atomic mass = number of protons + number of neutrons = 4+5 = 9 amu
Answer:
magnitude of force on charge 2Q = 
Direction of force on charge = 61 ⁰
Explanation:
The magnitude on the force on the charge can be evaluated by finding the net force acting on the charge 2Q i.e x-component of the net force and the y-component of the net force
║F║ = 
= after considering the forces coming from Q, 3Q and 4Q AND APPLYING COULOMBS LAW
magnitude of force acting on 2Q =
The direction of the force on charge 2Q is calculated as
tan ∅ = 
= 1.8284
therefore ∅ = 
1.8284
= 61⁰
Answer:
a) During the reaction time, the car travels 21 m
b) After applying the brake, the car travels 48 m before coming to stop
Explanation:
The equation for the position of a straight movement with variable speed is as follows:
x = x0 + v0 t + 1/2 a t²
where
x: position at time t
v0: initial speed
a: acceleration
t: time
When the speed is constant (as before applying the brake), the equation would be:
x = x0 + v t
a)Before applying the brake, the car travels at constant speed. In 0.80 s the car will travel:
x = 0m + 26 m/s * 0.80 s = <u>21 m </u>
b) After applying the brake, the car has an acceleration of -7.0 m/s². Using the equation for velocity, we can calculate how much time it takes the car to stop (v = 0):
v = v0 + a* t
0 = 26 m/s + (-7.0 m/s²) * t
-26 m/s / - 7.0 m/s² = t
t = 3.7 s
With this time, we can calculate how far the car traveled during the deacceleration.
x = x0 +v0 t + 1/2 a t²
x = 0m + 26 m/s * 3.7 s - 1/2 * 7.0m/s² * (3.7 s)² = <u>48 m</u>
Answer:
P = 140000 [Pa]
Explanation:
To solve this problem we must remember that pressure is defined as the relationship between Force on the area of a body.
In this particular problem, we are given the force acting on the upper surface of the block, including the force exerted by the atmospheric pressure.
P = F/A
where:
P = pressure [Pa] (units of Pascals)
F = force = 3.5*10⁴ [N]
A = area = 0.25 [m²]
P = 3.5*10⁴/0.25
P = 140000 [Pa]
