Answer:
Smaller refractive power
Explanation:
The refractive power of an eye is the extent to which it can converge or diverge the light rays.
Near point is the the closest point for an eye such that when an object is placed at that point the image it forms is sharp and clearly visible to the eye.
A the person ages, the ciliary muscles of the eyes weakens and as a result the lens contracts and the formation of the image takes place behind the retina instead of forming at the retina.
Thus the near point also increases and the refractive power becomes smaller.
Answer:
here 20 lb object will hit the ground first
Explanation:
Acceleration of the object while it is dropped in air is given as



so acceleration of the object is independent of the mass of the object
now time to reach the ground is given as


for 20 pound object


for 50 pound object


Answer:
The increase in gravitational potential energy is the same in both cases
Explanation:
It is easier to climb a mountain in a zigzag way rather than climbing on a straight line but since the distance is the same ( vertical height ) , mass and gravity is the same. Hence the increase in gravitational potential energy is the same in both cases.
gravitational potential energy = mgh ( same in both cases )
m = mass
g = acceleration due to gravity
h = distance ( vertical height )
Answer:
Other than the fact that momentum is a "vector" quantity I wouldn't know.
If the car had a momentum opposite to the chosen positive direction then its total momentum would be negative.
Answer:
τ = 0.00203 seconds
Explanation:
The time constant τ in a R-L circuit is given by
τ = L/R
First we have to find out the equivalent resistance of the circuit.
Since there is a parallel combination of 19 Ω and 6.0 Ω resistor
Req = 19*6/19+6
Req = 4.56 Ω
Now we can find out the time constant
τ = L/R
τ = 0.0093/4.56
τ = 0.00203 seconds
Therefore, the time constant of this circuit is 0.00203 seconds.