The quest to put Americans on the moon before the Soviets do. During the Space Race, a couple of astronauts went up into space only to be tragically killed in an explosion.
Answer: B. 44.64 g
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Mass of reactants = mass of iron + mass of oxygen = mass of iron + 34.7 g
Mass of product = mass of iron oxide = 79.34 g
As Mass of reactants = Mass of product
mass of iron + 34.7 g = 79.34 g
mass of iron = 44.64 g
Thus 44.64 g of iron was used in the reaction
Answer:
baking the cake batter
Explanation:
Baking the cake batter will indicate that chemical change has occurred here. What is a chemical change?
- A chemical change is one in which a new kind of matter is formed.
- It is usually accompanied by energy either evolution or absorption of energy in form of heat or light or both.
- The process is irreversible.
- When the batter bakes, a new substance different from the cake mix is obtainable.
- We cannot get back the ingredient from this baked cake. It is impossible.
- This is good indicator of chemical change.
The formula to find the kinetic energy is:
Ek= 1/2 × m × v^2
1. Ek= 1/2×15×3^2
= 67.5 J
2.Ek= 1/2×8×4^2
=64 J
3.Ek= 1/2×12×5^2
= 150 J
4.Ek= 1/2×10×6^2
= 180 J
So the fourth dog has the most kinetic energy.
