Answer:
The system loses 90 kJ of heat
Explanation:
We can answer the question by using the 1st law of thermodynamics, which states that:
where
is the change in internal energy of the system
is the heat absorbed by the system (positive if absorbed, negative if released by the system)
is the work done by the system (positive if done by the system, negative if done by the surrounding on the system)
In this problem, we have:
is the work done (negative, because it is done by the surrounding on the system)
is the increase in internal energy
Using the equation above, we can find Q, the heat absorbed/released by the system:
And the negative sign means that the system has lost this heat.
Answer:
(a) P = 459.055 N.
(b) the refrigerator tips.
Explanation:
Given, the angle of ramp is 20°.
When the weight of refrigerator is resolved in directions parallel and perpendicular to ramp, 75×g×sin(20°) and 75×g×cos(20°).
⇒ normal contact force is 75×g×cos(20°).
⇒ frictional force is 0.3×75×g×cos(20°) = 207.414 N
so, total opposite force is 207.414 + 75×g×sin(20°) = 459.055 N.
so, the force needed is P = 459.055 N
And as the moment due to both opposite force and P force are in same direction the refrigerator tips rather than just sliding.
Answer:
Rs = 0.02008 Ω = 20.08 mΩ
Explanation:
The range of an ammeter can be increased by connecting a small shunt resistance to it in a series combination. This shunt resistance can be calculated by the following formula:
where,
= value of shunt resistance = ?
= current range of ammeter = 20 mA = 0.02 A
I = Required range of ammeter = 5 A
= Resistance of ammeter = 5 ohms
Therefore,
<u>Rs = 0.02008 Ω = 20.08 mΩ</u>
Answer:
15 protons and 18 electrons
General Formulas and Concepts:
<u>Chemistry</u>
- Reading a Periodic Table
- Element Number
- Neutral Atoms
- Ions
Explanation:
We are given the element P. P is 15 on the Periodic Table, meaning it has 15 protons and 15 electrons (all elements are in neutral form).
P³⁻ ion means the element now has a negative charge of 3. We know protons have a positive charge and electrons have a negative charge. 3- means we will have more electrons than protons.
Therefore, P³⁻ would have 15 protons and <em>18</em> electrons:
15 (+) + 18 (-) = 3 (-)
