Answer:
The photoelectric effect occurs only for frequencies above the cutoff frequency, regardless of the intensity.
Explanation:
The photoelectric effect occurs when light is shined on metals such as zinc beyond a certain frequency (the threshold frequency), which causes electrons to escape from the zinc. The electrons which are fleeing are called photo electrons.
Therefore photo electric effect is
The photoelectric effect occurs only for frequencies above the cutoff frequency, regardless of the intensity.
Answer:
See below ~
Explanation:
An object will sink in water when its density is greater than that of water, which is 1 g/cm³.
Volume of the box is <u>1331 cm³</u>. (11³)
Maximum mass of sand will be 1331 g. [because 1331/1331 = 1 g/cm³]
- Volume of sand = Mass of sand / Density of sand
- Volume (sand) = 1331/3.5
- Volume (sand) = 380.29 cm³
If the volume of sand is <u>greater than 380.29 cm³</u>, the box will sink in water.
Answer:
15 meters
Explanation:
The inicial energy of the ball is just potencial energy, and its value is:
E = m * g * h = m * g * 20,
where m is the ball mass, and g is the value of gravity.
In the moment that the ball strickes the ground, all potencial energy transformed into kinetic energy, and 25% of this energy is lost, so the total energy at this moment will be:
E' = 0.75 * E = 0.75 * m * g * 20 = 15*m*g
This kinetic energy will make the ball goes up again, and at the maximum height, all kinetic energy is transformed back into potencial energy.
So, as the mass and the gravity are constants, we can calculate the height the ball will reach:
E' = m*g*h = 15*m*g -> h = 15 meters
Answer:
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