To find or discover by investigation?
Answer:
1) The matter absorbs or reflects the light
2) Lens
3) <u><em>Concave</em></u>- curves inwards. Diverges light
b.<u><em>Convex</em></u>- curves outward. Converges light
4) The image is real if the distance of the object from the lens is greater than the focal length and virtual if it is less than the focal length
5) Lens and, for convex lenses, on the distance between the lens and the object.
6) Index of refraction?
Explanation:
I hope this helped you, sorry if anything is wrong
Given :
A mover slides a refrigerator weighing 650 N at a constant velocity across the floor a distance of 8.1 m.
The force of friction between the refrigerator and the floor is 230 N.
To Find :
How much work has been performed by the mover on the refrigerator.
Solution :
Since, refrigerator is moving with constant velocity.
So, force applied by the mover is also 230 N ( equal to force of friction ).
Now, work done in order to move the refrigerator is :

Hence, this is the required solution.
Answer:
4 (D): twice the voltage, and the same current will flow through each.
Explanation:
When we have batteries in series in a circuit, the equivalent voltage will be the sum of their voltages, and the current flowing through then will be the same.
These batteries are identical, so they have the same voltage, therefore when they are put in series, the equivalent voltage will be twice the voltage of one battery.
So the correct option is 4 (D): twice the voltage, and the same current will flow through each.
Answer:
The degree of reflection whether faint or bright you see on the surface of an object is an indication that light particles had hit the surface. Since light is a wave and as part of its characteristics can get reflected. However, the amount of light reflected by a surface is dependent on the smoothness of the surface which can be shiny or dull, it can also be dependent on the nature of the surface which can be glass, water, and so on. So, from the question, you can see a faint reflection on the surface of a shiny plate or cup because of the smoothness of the surface which reflects the lights that hit it from a particular direction at the same angle.