Number 20 is B and 21 is C
Answer:
40479.6 J
Explanation:
Applying,
q = cm(t₂-t₁).................... Equation 1
Where q = change in heat content of the system, c = specific heat capacity of the system, m = mass of the system, t₁ = initial temperature, t₂ = final temperature.
From the question,
Given: m = 79 g = 0.079 kg, t₁ = 21°C, t₂ = 143°C
Constant: c = 4200 J/kg.°C
Substitute these values into equation 1
q = 4200(0.079)(143-21)
q = 331.8(122)
q = 40479.6 J
Answer:
<h2>
D.)</h2>
Explanation:
Potential energy is when a object is not in motion and the ball is sitting on a shelf not being thrown around or rolling. kinetic energy is when a obeject is in motion and moving.
Answer:
<u>Question 2</u>
<u>Part (a)</u>
Chlorine: type of compound = chloride
Oxygen: type of compound = oxide
<u>Part (b)</u>
The iron reacts with water and oxygen to form rust.
A water molecule is made up of two hydrogen atoms joined to one oxygen atom: Di-hydrogen oxide.
<u>Question 3</u>
This circuit is in parallel.
The current in a parallel circuit splits into different branches then combines again before it goes back into the supply.
We are told that A₁ = 0.8 A
As the lamps have <u>equal resistance</u>, the current splits equally:
A₂ = 0.4 A
A₃ = 0.4 A
Then combines again:
A₄ = 0.8 A
