Answer:
Explanation:
Work done in lifting the weight once = mgh
= 20 x 9.8 x (1.9+1.7)
= 705.6 J
= 705.6 / 4.2 calorie
= 168 cals
Total energy to be spent = 600 x 10³ cals
No of times weight is required to be lifted
= 600 x 10³ / 168
= 3.57 x 10³ times
Total time to be taken = 2 x 3.57 x 10³
= 7.14 x 10³ s
=119 minutes .
The similarities and the differences between gravitational and electric force are listed below
Explanation:
- The magnitude of the gravitational force between two objects is given by Newton's law of gravitation:
where
is the gravitational constant
are the masses of the two objects
r is the separation between them
- Coloumb's law gives instead the strength of the electrostatic force between two charged objects, which is
where:
is the Coulomb's constant
are the two charges
r is the separation between the two charges
By comparing the two equations, we find the following similarities:
- Both the forces are inversely proportional to the square of the distance between the two objects,
- Both the forces are proportional to the product between the "main quantity" of each force, which is the mass for the gravitational force (
) and the charge for the electric force (
Instead, we have the following differences:
- The gravitational force is always attractive, since the sign of
is always positive, while the electric force can be either attractive or repulsive, since the sign of 
can be either positive or negative - The value of the gravitational costant G is much smaller than the value of the Coulomb's constant, so the gravitational force is much weaker than the electric force
Learn more about gravitational force and electric force:
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Answer:
A. Thermal energy will move from the water to the ice.
B. Thermal energy will move from air to the water.
C. Thermal energy will move from the ice to the air.
D. Thermal energy will move from the water to the air.
A and B are correct
Explanation:
Because thermal energy will move from the water to the ice
Batteries are connected when the terminal voltage across each of them was measured because batteries have an internal resistance that is in series with the load.
<h3>What is a chemical reaction?</h3>
A chemical reaction is a process in which one or more substances, also known as reactants are converted to one or more different substances, known as products. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products
In batteries, the chemical energy is converted into electrical energy with help of a chemical reaction happening inside the battery.
Batteries and other power sources have an internal resistance that runs parallel to the load. The overall resistance of the path of the electron flow inside the source constitutes the internal resistance, which is not technically a resistor. Usually, internal resistance is extremely minimal.
Thus, considering the internal resistance of the batteries, the terminal voltage across each of them was measured.
Learn more about chemical reactions here
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Hi there!
a)
We can find the angular velocity at t = 2.0 s by plugging in this value into the equation.
b)
The angular acceleration is the derivative of the angular velocity, so:
Thus, the angular acceleration is a <u>constant 25 rad/s².</u>
