Answer:
The power of the corrective lenses is 3.162 D.
Explanation:
Given that,
Object distance = 70 cm
Image distance = 62 cm
Distance between eyes and glasses = 2.5 cm
Eyeglasses made of diverging corrective lenses can help her to see the apple clearly
So now ,
Object distance from glass =70-2.5 = 67.5 cm
Image distance from glass = 62-2.5 = 59.5 cm
We need to calculate the focal length
Using formula for focal length
We need to calculate the power of lens
Using formula of power
Negative sign shows the lens is diverging.
Hence, The power of the corrective lenses is 3.162 D.
Answer: a) the force will be repulsive
b) the ratio of the new force to the old force will be 2
c) O
Explanation:
a) since charge -Q is moved from A to B, this implies that sphere A is negatively charged. The two spheres are now negatively charged and will repel themselves.
b) initial force will be -q(-Q)/d2
Adding extra charge -Q will cause change on B to become -2Q
The new force will be - 2Q(-q)/d2
Dividing new force by old force will give 2
C) if B is neutralized, the net charge becomes 0 and there will be no force on it.
Answer:
The increase in the gravitational potential energy is 29.93 joules.
Explanation:
Given that,
Mass of the box, m = 2.35 kg
It is lifted from the floor to a tabletop 1.30 m above the floor, h = 1.3 m
We need to find the increase the gravitational potential energy. Initial it will placed at ground i.e. its initial gravitational potential is equal to 0. The increase in the gravitational potential energy is given by :
U = 29.93 Joules
So, the increase in the gravitational potential energy is 29.93 joules. Hence, this is the required solution.
Answer:
A. Power = Work / Time
Explanation:
Power is the amount of work done over time, or rather the rate of work, which is given by the unit of watts (W). Since work is defined by Force * Displacement, we can also say Power = Force * Displacement / Time.
