Answer:
C. At the instant the ball reaches its highest point.
Explanation:
When a body is thrown up, it tends to come down due to the influence of gravitational force acting on the body. The body will be momentarily at rest at its maximum point before falling. At this maximum point, the velocity of the body is zero and since force acting on a body is product of the mass and its acceleration, the force acting on the body at that point will be "zero"
Remember, F = ma = m(v/t)
Since v = 0 at maximum height
F = m(0/t)
F = 0N
This shows that the force acting on the body is zero at the maximum height.
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>
Answer:
hi what is your question?? say in English please
Hello!
Use the equation F = m · a (Newton's Second Law) to solve. Substitute in the given values:
F = 5 · 20
F = 100N
