What percent of my Iodine-131 sample will be left after 7 half-lives?

How do meteorites differ from meteors and meteoroids?

According to the law of conservation of energy what ultimatly happens to the total amount of energy in the universe?

In 1 km races, runner 1 on track 1 (with time 2 min, 28.13 s) appears to be faster than runner 2 on track 2 (2 min, 28.48 s). however, the length l2 of track 2 might be slightly greater than the length l1 of track 1.

What will the magnetic field of a long hole pipe carrying a current will be

Coulomb is a very large unit for practical use. Justify your answer if 10^10 electrons are transferred from a body/second

Which is the most important radiation conduction or convection? Explain

A compressed spring has 16.2 J of elastic potential energy when it is compressed 0.30 m. What is the spring constant of the spring?

A smart phone charger delivers charge to the phone, in the form of electrons, at rate of - 0.75 C/s. How many electrons are delivered to the phone during 45 min of charging?

Which type of wave can transmit energy through a vacuum?

You wad up a piece of paper and throw it into the wastebasket. How far will your piece of paper travel if you throw it with a velocity of 4.