Answer:
D. 4Al + 3O2 → 2Al2O3
Explanation:
Chemical reactions involves the chemical combination of two or more substances called REACTANTS to yield other substances called PRODUCTS. However, in accordance with the LAW OF CONSERVATION OF MASS, the amount of reactants must be equal to that of the products.
To accomplish this, the reaction must be BALANCED. A balanced equation is an equation in which the number of atoms of each element in the reactant side equals the number of atoms in the product side. In this reaction involving Aluminum and Oxygen to give Aluminum oxide as follows:
Al + 02 → Al2O3
A coefficient is used to balance the number of atoms on both sides of the equation as follows:
4Al + 3O2 → 2Al2O3
it is warmer because it is closer to the equator and the equator is the warmest tropical point
1) The braking force is provided by the frictional force, which is given by:
where
is the coefficient of friction
m=1500 kg is the mass of the car
is the gravitational acceleration
Substituting numbers into the equation, we find
2) The work done by the frictional force to stop the car is equal to the product between the force and the distance d:
(1)
where we put a negative sign because the force is in the opposite direction of the motion of the car.
3) For the work-energy theorem, the work done by the frictional force is equal to the variation of kinetic energy of the car:
(2)
The final kinetic energy is zero, so the variation of kinetic energy is just equal to the initial kinetic energy of the car:
4) By equalizing eq. (1) and (2), we find the distance, d:
Answer:
134 kg
Explanation:
The snowmobile is moving at constant speed, so the acceleration is 0.
Sum of the forces in the x direction:
∑F = ma
F − 360 = 0
F = 360
Friction force equals the normal force times the coefficient of friction:
Nμ = 360
On level ground, the normal force equals the combined weight:
(m + 50)g μ = 360
m + 50 = 360 / (gμ)
m = -50 + 360 / (gμ)
m = -50 + 360 / (9.8 × 0.2)
m ≈ 134 kg
Round as needed.
