Both positive work and negative work have meaning: Positive work follows when the force has a component parallel to the displacement. Positive work adds energy to a system. Negative work follows when the force has a component opposite or against the displacement.
Answer: option 1 : the electric potential will decrease with an increase in y
Explanation: The electric potential (V) is related to distance (in this case y) by the formulae below
V = kq/y
Where k = 1/4πε0
Where V = electric potential,
k = electric constant = 9×10^9,
y = distance of potential relative to a reference point, ε0 = permittivity of free space
q = magnitude of electronic charge = 1.609×10^-19 c
From the formulae, we can see that q and k are constants, only potential (V) and distance (y) are variables.
We have that
V = k/y
We see the potential(V) is inversely proportional to distance (y).
This implies that an increase in distance results to a decreasing potential and a decrease in distance results to an increase in potential.
This fact makes option 1 the correct answer
Answer:
Explanation:
Velocity of sound in air at 20 degree = 343 m/s
Velocity of sound in water at 20 degree = 1470 m/s
Time taken in to and fro movement in air
=( 2 x 10) / 343 = 0.0583 s
Rest of the time is
.171 - .0583 = .1127 s
This time is taken to cover distance in water. If d be the depth of lake
2d / velocity = time taken
2 d / 1470 = .1127
d = 82.83 m
You are at rest with respect to the car.
You are in motion with respect to the School.
