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
Answer:
19.6 m/s
Explanation:
The parameters given are:
Mass M = 20 Kg
Force F = 285 N
Angle Ø = 30 degree
Time t = 4 seconds
Coefficient of friction = 0.72
At the plane, the weight of the box will be mgsinØ
Resolving forces at the plane, we will have:
MgsinØ + Fr = F
Where Fr = frictional force.
Fr = F - mgsinØ
Substitute all the parameters into the formula
Fr = 285 - 20 × 9.8 sin30
Fr = 285 - 98
Fr = 187 N
But for the box moving toward the top of the plane,
F - Fr = ma
Where a = V/t
Substitute all the parameters involved into the formula
285 - 187 = 20 ( V/4)
98 = 5V
V = 98/5
V = 19.6 m/s
Therefore, the speed with which the box is moving is 19.6 m/s
Answer:
I) angle of reflection = 48 degrees
II) angle of deviation = 0
Explanation:
Given that the:
angle of incident = 48º.
According to law of reflection which state that the angle of incident is equal to the angle of reflection.
I.) Therefore,
angle of reflection = 48º.
II.) There can only be deviation if the mirror has a diffused surface. But for a smooth plane mirror, there can never be any deviation.
Therefore ,
The angle of deviation = 0
The answer is either B or C
Answer:
First one,
Its because
Downward force must greater to uplift its weight.
From 3rd law of motion
