Answer:
a ) 2.13 X 10⁶ m/s .
b ) 1.28 X 10⁶ m/s
Explanation:
When electrons are repelled by negative plates and attracted by positive plates , it will increase their kinetic energy.
Increase in their energy = 4.15 eV
= 4.5 X 1.6 X 10⁻¹⁹ J
= 6.64 x 10⁻¹⁹ J
Initial kinetic energy
= 1/2 mv²
= 1/2 x 9.1 x 10⁻³¹ x ( 1.76 x 10⁶)²
= 14.09 X 10⁻¹⁹ J
Total energy
= 6.64 x 10⁻¹⁹+14.09 X 10⁻¹⁹
= 20.73 x 10⁻¹⁹
If V be the increased velocity
1/2 m V² = 20.73 X 10⁻¹⁹
.5 X 9.1 X 10⁻³¹ V² = 20.73 X 10⁻¹⁹
V = 2.13 X 10⁶ m/s .
b ) When electrons are released from positive plate , their speed are reduced because of attraction between electrons and positively charge plates.
Initial kinetic energy
= 14.09 x 10⁻¹⁹ J (see above )
reduction in kinetic energy
= 6.64 x 10⁻¹⁹ J ( See above )
Total energy with electron -
= 14.09 x 10⁻¹⁹ - 6.64 x 10⁻¹⁹
= 7. 45 x 10⁻¹⁹ J .
If V be the energy of electrons reaching the negative plate,
1/2 m V² =7. 45 x 10⁻¹⁹
V = 1.28 X 10⁶ ms⁻¹
What? Do you have a picture of the problem ?
Answer:
A <u>scientific model</u> is a physical and/or mathematical and/or conceptual representation of a system of ideas, events or processes. Scientists seek to identify and understand patterns in our world by drawing on their scientific knowledge to offer explanations that enable the patterns to be predicted.
Answer: Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn, and Jupiter.
Explanation:
That's all of the planets if you need them. Hope this helps!
Answer:
D
Explanation:
D) The overall work done by gravity is zero
This statement is correct .
If m be the mass of each of the children and h be the height of tower
work done by gravity on the boys in going up = - mgh
it is so because force applied by gravity = mg downwards and displacement
is upwards
work done will be negative = - mgh
Work done by gravity on boys when they come down = + mgh because both force and displacement are downwards .
Hence total work done = - mgh + mgh = 0.
The children will have same kinetic energy as the inclined surface is friction-less so no energy will be dissipated hence addition of energy to boys in both the cases will be same.