Answer:
Option B
the type of light and the material of the lens
Explanation:
Since the experiment focuses on investigating how thickness of a lens affects the point where a beam of light, it means thickness of lens here are indepedent variable since Lydia has control over the thickness and can alter it. However, the point where beam of light focuses on is depedent variable since Lydia will just observe the point but can't change it. To ensure that other external factors don't affect the results, Lydia has to ensure that the type of material irrespective of thickness remain constant and also the source of light must be kept constant. Therefore, the controls will be the type of light and the material of the lens
Answer:
E=252J
Explanation:
The total mechanical energy of an object or system is given by:
E mech=K+U
Where K is the kinetic energy of the object and U is the potential energy of the object. The carriage, sitting motionless at the top of the hill, has only potential energy in the form of gravitational potential energy.
Gravitational potential energy is given by:
Ug=mgh
Where m is the mass of the object, g is the gravitational acceleration constant, and h is the height of the object above some specific reference point, in this case the ground 21 m below.
The weight of a stationary object at the surface of the earth is equal to the force of gravity acting on the object.
W=→Fg=mg
We are given that the carriage weighs 12 N, therefore mg=12N.
Ug=12N⋅21m
⇒Ug=252Nm=252J
Hope it helped, God bless you!
<span>Soil conservation involves protecting soil quality and preventing erosion.
Answer: A</span>
When the metal wire in an incandescent lightbulb glows when the light is switched on and stops glowing when it is switched off, this is an example of resistance, which provides light and heat.
Answer:
Explanation:
Cutting a string in half because
b is irreversible
c is a cheical and d is also a chemical change
