Answer:
0.7515875 eV

Explanation:
f = Maximum frequency = 
h = Planck's constant = 
W = Work function = 2.52 eV
Converting to Joules

Maximum photon energy is given by

Maximum Kinetic energy is given by

Converting to eV

The maximum kinetic energy of electrons ejected from this surface is 0.7515875 eV

The range of frequencies for which no electrons are ejected is

Answer:
Mass of object (m) = 5.102 kg
Explanation:
Given:
Horizontal Force (F) = 50 N
Find:
Mass of object (m) = ?
Computation:
We know that, acceleration due to gravity (g) = 9.8 m/s²
⇒ Horizontal Force (F) = mg
⇒ 50 N = m (9.8 m/s²)
⇒ Mass of object (m) = 50 / 9.8
⇒ Mass of object (m) = 5.102 kg
Mass of object (m) is 5.1 kg (Approx)
Answer:

Explanation:
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Actually, they're not. There's a group of stars and constellations arranged
around the pole of the sky that's visible at any time of any dark, clear night,
all year around. And any star or constellation in the rest of the sky is visible
for roughly 11 out of every 12 months ... at SOME time of the night.
Constellations appear to change drastically from one season to the next,
and even from one month to the next, only if you do your stargazing around
the same time every night.
Why does the night sky change at various times of the year ? Here's how to
think about it:
The Earth spins once a day. You spin along with the Earth, and your clock is
built to follow the sun . "Noon" is the time when the sun is directly over your
head, and "Midnight" is the time when the sun is directly beneath your feet.
Let's say that you go out and look at the stars tonight at midnight, when you're
facing directly away from the sun.
In 6 months from now, when you and the Earth are halfway around on the other
side of the sun, where are those same stars ? Now they're straight in the
direction of the sun. So they're directly overhead at Noon, not at Midnight.
THAT's why stars and constellations appear to be in a different part of the sky,
at the same time of night on different dates.
Answer:
Explanation:
Total length of the wire is 29 m.
Let the length of one piece is d and of another piece is 29 - d.
Let d is used to make a square.
And 29 - d is used to make an equilateral triangle.
(a)
Area of square = d²
Area of equilateral triangle = √3(29 - d)²/4
Total area,

Differentiate both sides with respect to d.

For maxima and minima, dA/dt = 0
d = 8.76 m
Differentiate again we get the

(a) So, the area is maximum when the side of square is 29 m
(b) so, the area is minimum when the side of square is 8.76 m