We know that domestic dogs are descended from wolves. Exactly when and how this occurred is still being studied; many experts indicate that dogs were first domesticated about 12,000 years ago, but a few DNA studies indicate a much earlier date for the split between the wolf and the dog, perhaps as long ago as 130,000 years.
Regardless of the exact timing of the divergence between wolves and dogs, one thing is true: both species display quite a bit of genetic diversity, particularly in size and coloration.In order to breed a dog of a specific size, all one has to do is choose parents with the appropriate variations. For instance, if you want to create a small dog breed, you would just breed the smallest dogs you have, then you would choose their smallest offspring to breed the next generation, and so on until you have reached the desired size.
Q = mcΔθ
67.5 = m x 0.45 x (28.5 - 21.5)
M = 67.5 / 3.15
= 21.4 g
Answer:
How much heat energy required to convert following?
How much heat energy, in kilojoules, is required to convert 47.0 g of ice at -18.0 C to water at 25.0 C ?
Specific Heat of Ice - 2.09 j/g * c
This is how I did it and the answer is wrong...Please check and correct me
Q = m * Cice * Change in Temp
Q = (47.0 g)(2.09 J/g*c)(43) = 4222.6 J * 0.001 kj / j = 4.22 kj
Answer:
This involves negatively charged particles (electrons) jumping to positively charged objects. When you rub the balloons against the fabric they become negatively charged. They take some of the electrons from the fabric and leave them positively charged.
Explanation:
Negative charges attract to positive charges. If a balloon is not rubbed with the wool cloth, it has an equal amount of negative to positive charges, so it will attract to a rubbed balloon. When both balloons are rubbed with the wool cloth, the both receive negative charges, so they will repel each other.