If the box is moving at constant velocity, net force must be zero, so:
F + fr = 0
fr = -F
<u>fr = -40 N</u>
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
Answer
given,
gauge pressure = 1.94 x 10⁵ Pa
Pressure due to 4.90 m column of water
= ρ g h
= (4.90) x (1000) x (9.8) Pa
= 48020 Pa
Gauge pressure of second floor faucet
= 1.94 x 10⁵Pa - 48020 Pa
P_g= 145980 Pa
( b )
Let h = height of faucet from which no water can flow even if open
P = ρ g h
1.94 x 10⁵ = h x(1000) x (9.8)
h = 19.79 m
Answer:
The heat transferred into the system is 183.5 J.
Explanation:
The first law of thermodynamics relates the heat transfer into or out of a system to the change of internal and the work done on the system, through the following equations.
ΔU = Q - W
where;
ΔU is the change in internal energy
Q is the heat transfer into the system
W is the work done by the system
Given;
ΔU = 155 J
W = 28.5 J
Q = ?
155 = Q - 28.5
Q = 155 + 28.5
Q = 183.5 J
Therefore, the heat transferred into the system is 183.5 J.
Answer:
I think they use it at night because they want to avoid involving themselves in road accident while crossing the street. When there are reflective strips on their clothes, drivers do notice them even at far ends of the street since the strips will reflect the rays from the car lights to the driver,hence, the driver notifies that there is a pedestrian crossing and therefore slows down.
