Answer:
In a collision, the velocity change is always computed by subtracting the initial velocity value from the final velocity value. If an object is moving in one direction before a collision and rebounds or somehow changes direction, then its velocity after the collision has the opposite direction as before.
Answer:
A control variable in scientific experimentation is an experimental element which is constant and unchanged throughout the course of the investigation.
Explanation:
Therefore electric potential is V = 15000V.
What is electric potential?
The amount of labor required to convey a unit of electric charge from a reference point to a given place in an electric field is known as the electric potential (also known as the electric field potential, potential drop, or the electrostatic potential).
length of sparks d = 5 mm = 5 x 10^-2 m
(a) It is possible to find average values for the skin's surface and the electric field in dry air from outside sources. Electric field and spark length can be used to determine electric potential.
V = E.d
V = 15000V
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In exothermic reactions, heat and light are released to the surrounding environment. On the other hand, in an endothermic reaction, heat is required and therefore it can be considered as a reactant.
- In exothermic reactions, light and heat are released into the environment (Option D).
- Exothermic reactions release energy in the form of heat or light.
- Combustion reactions are generally exothermic reactions.
- After an exothermic reaction takes place it is possible to observe that the energy of the products of the reaction is lesser than the energy of the reactants.
- The energy released in exothermic reactions is evidenced by the increase in temperature of the reaction.
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<span>The maximum possible efficiency, i.e the efficiency of a Carnot engine , is give by the ratio of the absolute temperatures of hot and cold reservoir.
η_max = 1 - (T_c/T_h)
For this engine:
η_max = 1 - [ (20 +273)K/(600 + 273)K ] = 0.66 = 66%
The actual efficiency of the engine is 30%, i.e.
η = 0.3 ∙ 0.664 = 0.20 = 20 %
On the other hand thermal efficiency is defined as the ratio of work done to the amount of heat absorbed from hot reservoir:
η = W/Q_h
So the heat required from hot reservoir is:
Q_h = W/η = 1000J / 0.20 = 5000J</span>