Answer:
D. The cart is moving at a constant speed or velocity
Explanation:
Equilibrium is a state of body in which it is either at rest or moves with uniform velocity. The sum of forces acting on such a body is always zero and the sum of all the torques acting on it is also zero.
There are two types of equilibrium as follows:
Static Equilibrium: When a body is at rest it is said to be in static equilibrium.
Dynamic Equilibrium: When a body is moving with constant velocity, then it is said to be in dynamic equilibrium.
Hence, the correct option here will be:
<u>D. The cart is moving at a constant speed or velocity</u>
Answer:60 gm
Explanation:
Given
initial velocity of ball 
Force exerted by racquet 
time period of force 
final velocity of ball 
Racquet imparts an impulse to the ball which is given by
The energy of the photon emitted when an electron in a mercury atom drops from energy level f to energy level b is 3.06 eV.
<h3>Change in energy level of the electron</h3>
When photons jump from a higher energy level to a lower level, they emit or radiate energy.
The change in energy level of the electrons is calculated as follows;
ΔE = Eb - Ef
ΔE = -2.68 eV - (-5.74 eV)
ΔE = 3.06 eV
Thus, the energy of the photon emitted when an electron in a mercury atom drops from energy level f to energy level b is 3.06 eV.
Learn more about energy level here: brainly.com/question/14287666
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Answer:
d. perfectly elastic
Explanation:
According to the kinetic theory for collisions of gas molecules:
1.The loss of energy is negligible or we can say that it is zero.
2.Molecules of the gas move in a random manner.
3.The collision between molecules and with the wall of the container is perfectly elastic.That is why loss in the energy is zero.
Therefore the correct answer will be d.
d. perfectly elastic
