Answer:
Force the floor exerts on the passenger is 833 N.
Explanation:
- Weight of passenger (
) = mg = 85 × 9.8 N = 833 N
- Force the floor exerts on the passenger (
) = ?
- For the elevator with the speed as 2.0 m/s the net force is zero, it means that the force is balanced.
i.e.
= -
= -mg = 833 N
hence
is 833 N
- If the lift was not at a constant speed i.e. if it had acceleration (
) then the case would be different.
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
PE = mgh
where
m = mass
g = acceleration due to gravity
h = height
Answer:
<em>113.4 J</em>
Explanation:
<u>Elastic Potential Energy</u>
Is the energy stored in an elastic material like a spring of constant k, in which case the energy is proportional to the square of the change of length Δx and the constant k.

The spring has a natural length of 0.7 m and a spring constant of k=70 N/m. When the spring is stretched to a length of 2.5 m, the change of length is
Δx = 2.5 m - 0.7 m = 1.8 m
The energy stored in the spring is:

PE = 113.4 J
Answer:
–735.17 N
The negative sign indicate that the force is acting in opposition direction to the car.
Explanation:
The following data were obtained from the question:
Mass (m) of car = 782.10 kg
Initial velocity (u) = 7.60 m/s
Final velocity (v) = 3.61 m/s
Time (t) = 4.23 s
Force (F) =?
Next, we shall determine the acceleration of the car. This can be obtained as follow:
Initial velocity (u) = 7.60 m/s
Final velocity (v) = 3.61 m/s
Time (t) = 4.23 s
Acceleration (a) =?
a = (v – u) / t
a = (3.61 – 7.60) / 4.23
a = –3.99 / 4.23
a = –0.94 m/s²
Finally, we shall determine the force experienced by the car as shown below:
Mass (m) of car = 782.10 kg
Acceleration (a) = –0.94 m/s²
Force (F) =?
F = ma
F = 782.10 × –0.94
F = –735.17 N
The negative sign indicate that the force is acting in opposition direction to the car.