Answer: a = 0.4m/s^2 - 9.8*c where c is the coefficient of kinetic friction of the surface
Explanation: We know that, by the second Newton's law, a = F/m
where a is the acceleration, F is the net force and m is the mass of the object.
Then, if the surface is frictionless, the total force applied in the object is 10N, and the mass of the object is 25kg, so the acceleration is:
a =10N/25kg = 0.4m/s^2.
But if the surface is frictional, there will be a force of friction applied in the mass (this depends on the coefficient of friction and the weight of the mass), this means that the acceleration will be reduced.
If = -(9.8*25)*c
where c is a number that is bigger than 0 and smaller than 1, is called the coefficient of kinetic friction.
So the total force is now:
F = (10 - 9.8*25*c)
Then, the acceleration in a frictional surface is equal to:
a = (10 - 9.8*25*c)/25 = 0.4m/s^2 - 9.8*c
Answer:
C. Count the atoms in each substance in the reactants and products.
Explanation:
A chemical reaction can be defined as a chemical process which typically involves the transformation or rearrangement of the atomic, ionic or molecular structure of an element through the breakdown and formation of chemical bonds to produce a new compound or substance.
In order for a chemical equation to be balanced, the condition which must be met is that the number of atoms in the reactants equals the number of atoms in the products.
This ultimately implies that, the mass and charge of the chemical equation are both balanced properly.
In Chemistry, all chemical equation must follow or be in accordance with the Law of Conservation of Mass, which states that mass can neither be created nor destroyed by either a physical transformation or a chemical reaction but transformed from one form to another in an isolated (closed) system.
One of the step used for balancing chemical equations is to count the atoms in each substance in the reactants and products.
For example;
NH3 + O2 -----> NO + H2O
The number of atoms in each chemical element are;
For the reactant side:
Nitrogen, N = 1
Hydrogen, H = 3
Oxygen, O = 2
For the product side;
Nitrogen, N = 1
Hydrogen, H = 2
Oxygen, O = 2
When we balance the chemical equation, we would have;
NH3 + 3O2 -----> 4NO + 2H2O
Answer:
Potential energy of book = 7.5 J
Explanation:
Given:
Weight of book = 5 N
Height of shelf = 1.5 meter
Find:
Potential energy of book
Computation:
Weight = Mass x Acceleration of gravity
Mass x Acceleration of gravity = 5 N
Potential energy = Mass x Acceleration of gravity x Height
Potential energy of book = Mass x Acceleration of gravity x Height
We know that;
Mass x Acceleration of gravity = 5 N
So,
Potential energy of book = 5 x 1.5
Potential energy of book = 7.5 J
Potential energy = (weight) x (height)
After the car has been raised 2.5 meters, it has
(11,000) x (2.5) = 27,500 Joules
MORE potential energy than it had before it was lifted.
That's the energy that has to come from the work you do to lift it.
Since no mechanical process is ever 100% efficient, the work required
to accomplish this task is <em>at least 27,500 joules</em>.
