Energy is the ability to do work.
So work can not be done without the transfer of energy from one body to another.
Work is the transfer of energy.
Answer:
Net force, F = 205.59 N
Explanation:
Given that,
Mass of a bobsled, m = 89 kg
Initial speed of the bobsled, u = 0
Distance travelled, d = 33.8 m
Final speed of the bobsled, v = 12.5 m/s
To find,
The magnitude of the net force
Solution,
Let a is the acceleration of the bobsled. Using the third equation of kinematics as :
Let F is the magnitude of net force acting on the bobsled. It can be calculated as :
F = 205.59 N
Therefore, the magnitude of the net force acting on the bobsled is 205.59 N.
Answer:
A) weakly attracted
B) negative charge on end A with B remaining almost neutral
C) strongly repelled
Explanation:
A)
- As the negatively charged ball is brought close to the end A of the road, positive charges on this end try to move away from there, leaving a small negative charge in this end, as they are not free to move as in a conductor.
- As a consequence of this, the end A of the road will be weakly attracted by the negatively charged ball.
B)
- After several contacts between the ball and the end A of the rod, an appreciable quantity of negative charge has been deposited in the end A, repelling positive charges towards the end B.
- However, as the rod is an insulator, positive charges can't travel massively to the end B, so it remains almost neutral.
C)
- After repeated contacts that have deposited a significative negative charge on the end A (which can't distribute evenly as in a conductor), when the ball (negatively charged) is brought close to this end of the rod, as both bodies have the same type of charge, they will be strongly repelled each other.
ΔE = Ef - Ei = (Uf + Kf) - (Ui + Ki) = (mgh + 0) - (mgh +0)
ΔE = mghf - mghi = 1(9.8)(1.5) - 1(9.8)(2) = -4.9 J
The total energy of the system decreases by 4.9 J so that must mean that 4.9 J is converted into other forms of energy and in this case it is heat.
Answer:
f = c / y where y is the wavelength
f1 = 3 *10E8 m/s / .001 m = 3 * 10E11 / s
f2 = 3 * 10E8 m/s / 1 m = 3 * 10E8 / s