Answer: 65000 seconds
Explanation:
Given that,
Current (I) = 2 mA
(Since 1 mA = 1 x 10^-3A
2 mA = 2 x 10^-3A)
Charge (Q) = 130 C
Time taken for a fully charged phone to die (T) = ?
Recall that the charge is the product of current and time taken.
i.e Q = I x T
130C = 2 x 10^-3A x T
T = 130C / (2 x 10^-3A)
T = 65000 seconds (time will be in seconds because seconds is the unit of time)
Thus, it will take a fully charged phone 65000 seconds to die
Answer: Valence electrons
Valence electrons are those that are in the outermost or superficial layer of the atom, which means they have the highest energy compared to those of the inner layers.
Because of their position, it is easier for these electrons to interact with other atoms of their own element as well as different elements. This is done through the process of forming bonds when being attracted by other atoms.
I don't think that 4m has anything to do with the problem.
anyway. here.
A___________________B_______C
where A is the point that the train was released.
B is where the wheel started to stick
C is where it stopped
From A to B, v=2.5m/s, it takes 2s to go A to B so t=2
AB= v*t = 2.5 * 2 = 5m
The train comes to a stop 7.7 m from the point at which it was released so AC=7.7m
then BC= AC-AB = 7.7-5 = 2.7m
now consider BC
v^2=u^2+2as
where u is initial speed, in this case is 2.5m/s
v is final speed, train stop at C so final speed=0, so v=0
a is acceleration
s is displacement, which is BC=2.7m
substitute all the number into equation, we have
0^2 = 2.5^2 + 2*a*2.7
0 = 6.25 + 5.4a
a = -6.25/5.4 = -1.157
so acceleration is -1.157m/(s^2)
3.6 kg.
<h3>Explanation</h3>
How much heat does the hot steel tool release?
This value is the same as the amount of heat that the 15 liters of water has absorbed.
Temperature change of water:
.
Volume of water:
.
Mass of water:
.
Amount of heat that the 15 L water absorbed:
.
What's the mass of the hot steel tool?
The specific heat of carbon steel is 
.
The amount of heat that the tool has lost is the same as the amount of heat the 15 L of water absorbed. In other words,
.
.
.
