Answer:
D. Light only
Explanation:
This is because photoelectric effect is a phenomenon in which electrically charged particles are emitted from a material when light is incident on it.
The light generates the energy which causes the material to emit electrons.
These electrons are only emitted at certain values of light energy, this thus shows that the light has to be quantized since electrons are not emitted over a range of values of light energy.
Thus, to fully describe the photoelectric effect, only light needs to be quantized.
Answer:
hmax = 1/2 · v²/g
Explanation:
Hi there!
Due to the conservation of energy and since there is no dissipative force (like friction) all the kinetic energy (KE) of the ball has to be converted into gravitational potential energy (PE) when the ball comes to stop.
KE = PE
Where KE is the initial kinetic energy and PE is the final potential energy.
The kinetic energy of the ball is calculated as follows:
KE = 1/2 · m · v²
Where:
m = mass of the ball
v = velocity.
The potential energy is calculated as follows:
PE = m · g · h
Where:
m = mass of the ball.
g = acceleration due to gravity (known value: 9.81 m/s²).
h = height.
At the maximum height, the potential energy is equal to the initial kinetic energy because the energy is conserved, i.e, all the kinetic energy was converted into potential energy (there was no energy dissipation as heat because there was no friction). Then:
PE = KE
m · g · hmax = 1/2 · m · v²
Solving for hmax:
hmax = 1/2 · v² / g
Answer:
Our solar system has total eight planets out of which four are inner planets and four are outer planets. The four outer planets are Jupiter, Saturn, Uranus and Neptune. The common characteristics of outer planets is that they are gaseous planets. They are larger on size than the inner rocky planets and are faraway from Sun. They have larger period of revolution around the Sun.
Uranus is a gaseous planet and lies far from Sun and hence has large period of revolution. It takes 84 Earth years to revolve around Sun. This data indicates that Uranus resides in the outer region of the Solar System.
Answer:
The minutes hand travels 39.60 cm.
Explanation:
Note: a clock has a shape of a circle, the minutes hand is the radius, and the travel of the minutes hand forms a arc.
Length of an arc = ∅/360(2πr)
L = ∅/360(2πr).................... Equation 1π
Where L = length of an arc, ∅ = angle formed by an arc, r = radius of the arc.
Given: ∅ = 252°, r = 9 cm, π = 3.143.
Substituting these values into equation 1,
L = 252/360(2×3.143×9)
L = 0.7×2×3.143×9
L = 39.60 cm.
Thus the minutes hand travels 39.60 cm.
