The formular for determinatio of mass number is this:
Mass number = number of proton + number of neutron
From the question, we are told that:
Mass number = 39
Proton number = 19
Number of proton = ?
Number of neutron = mass number - number of proton
Number of neutron= 39 - 19 = 20
Therefore, number of neurtron = 20.
<span>So we want to know what happens to meteors that enter the Earth's atmosphere and experience air friction. So since most meteors that enter Earth's atmosphere are made out of ice and/or rocks, when they enter the atmosphere, they experience air friction and their temperature rises so high they either melt or burn up. So the correct answer is burns up. </span>
The ideal mechanical advantage of a lever (IMA) is given by:
Where:
Le = Effort of the arm
Lr = Resistance arm.
Therefore, we can increase the force adventage by increasing the effort arm or reducing the load arm
Answer:
a. Make the effort length longer.