<span>When a person lifts the block, the block has more potential energy. Therefore the person does positive work on the block.
work = m g h
work = (4.5 kg) (9.80 m/s^2) (1.2 m)
work = 52.92 joules
The person's work on the block is 52.92 joules
When the block is being raised, the force of gravity opposes the motion. Therefore the force of gravity does negative work on the block.
work = - (force) (h)
work = - m g h
work = -(4.5 kg) (9.80 m/s^2) (1.2 m)
work = -52.92 joules
The work done by the force of gravity on the block is -52.92 joules
Note that when the block is moved horizontally, the potential energy does not change. Therefore there is no work done on the block when it moves horizontally (we are assuming that the kinetic energy does not change).</span>
Answer: Option (C) is the correct answer.
Explanation:
When yeast is added into a bottle with water and sugar then after some time yeast becomes activated. This results in the formation of a chemical change as bubbles are formed on the surface of the mixture in the bottle.
This indicates that a gas has been released due to the chemical change.
Thus, we can conclude that most likely a chemical change has occurred because a gas was produced.
The ingredients do not react with or chemically bond to each other.
Because glucerin is hotter so it decreases faster
Answer:
Its duration is 1.85*10⁻³ s or 1.85 ms
Explanation:
The intensity of electric current I is defined as the amount of electric charge Q (measured in Coulombs) that passes through a section of a conductor in each unit of time. The letter I is used to name the Intensity and its unit is the Ampere (A).
The intensity of electric current is expressed as:
where:
I: Intensity expressed in Amps (A)
Q: Electric charge expressed in Coulombs (C)
t: Time expressed in seconds (s)
Being:
Replacing:
Solving:
19500 A*t= 36 C
t= 1.85*10⁻³ s= 1.85 ms (being 1 s= 1,000 ms)
<u><em>Its duration is 1.85*10⁻³ s or 1.85 ms</em></u>
