When is it clear that a balanced force are acting on an object?

Would it be correct to say the doppler effect is the apparent change in the speed of a wave due to the motion of the source? be sure to fully explain your position using at least 3 complete content related sentences.

Which are causes of mechanical weathering? (check all that apply) a. acid rain b. plant growth c. animal actions d. carbon dioxide e. pressure release i chose b & e and got the question wrong.

The gun from the crime scene shows tool marks where the serial numbers are ground off. there are also tool marks on the bullets left behind. what information can the tool marks on the bullets and gun provide about the crime? what type of evidence does this information provide, individual or class?