The cost of painting the traffic sign of 7.065 square feet is approximately equal to 25 dollar.
<u>Explanation:</u>
The cost of painting the circular traffic sign is given as 3.50 dollar per square feet. The diameter of the traffic sign is 36 inch, then its radius will be 
inches.
But as the cost is given in unit of feet, we have to convert the radius from inches to feet.
1 inches = 0.0833 feet
18 inches = 18 × 0.0833 feet
So, the radius of the traffic sign will be approximately equal to 1.5 feet.
The area of the traffic sign will be 
square feet.
So, if the cost of painting 1 square feet of traffic sign is 3.50 dollar, then
cost of painting 7.065 square feet of traffic sign = 3.50 × 7.065 = 24.7 dollar.
Thus, the cost of painting the traffic sign of 7.065 square feet is approximately equal to 25 dollar.
Answer:
C
Explanation:
Smooth muscles are in the digestive system, skeletal muscles are the ones we voluntarily move, and cardiac muscles are for the heart.
Answer:
The mass of the substance
- Dalton reported that seven pounds of Oxygen reacted with one pound of hydrogen to form water, but accurate modern experiment gives eight pounds to one.
- Lavoisier reported that water contains Oxygen 5.6 times more than hydrogen by weight.
- Dalton assumed that water contains 1 atom of oxygen and 1 atom of hydrogen and concluded that the relative weight of O must be 5.6 times as large as the H atom.
- By determining the relative mass we will be able to determine for example that one element has twice the mass of a second element.
Answer:
- <em><u>A physical change has occurred, with no energy change.</u></em>
Explanation:
When a pencil lead is broken there is not change of any chemical properties, therefore it is not a chemical change, but just a physical change. In this case the change is just the number of pieces and dimensions.
Chemical changes always involve the formation of new different substances; the bonds between the atoms of the starting substances (reactants) breake and new bonds are formed leading to new substances (products) with different chemical composition (arrange of atoms). Chemical changes occur through chemical reactions.
Hence, if there is not change on the chemical composition, you think on physical changes. Physical changes include change in shape, size, state of matter (e.g. solid, liquid, gas). In the case of a pencil lead breaking, it is a change in shape and size.
Also, since energy has not been absorbed or released during the change, the energy of the pencil lead before having been broken is equal to the sum of the energies of the pieces of pencil lead obtained. So, this is a physical change with no energy changes.
Some examples of physical changes that include change in energy are the change of state (e.g. solid to liquid or liquid to gas) and the dissolution of a compound.
