Calcium-51 has a half-life of 4.5 days. Only 0.75 gram remains of a sample that was initially 12 grams. How old is the sample of calcium-51? 4.5 days 9.0 days 13.5 days 18 days

If you were on the open ocean on a large ship, what steps would you do to determine the height of a wave?

Debbie places two shopping carts in a cart corral. She pushes the first cart, which then pushes a second cart. What force is being exerted? Debbie exerts force on the first shopping cart. The first cart exerts force on the second cart.

Explain how machines can be useful if the output is always less than the input work

A ball of mass 2 kg fallsfrom a rof that is 5 m above the ground. How much gravitational potential energy did the ball lose when it reached the ground, in units of joules? give your answer as a positive value

Leady oxide is a material that? s usually composed of A. 25% free lead and 75% lead oxide. B. 10% free lead and 90% lead oxide. C. 60% free lead and 40% lead oxide. D. 50% free lead and 50% lead oxide.

For each case, identify the force (including its direction) that causes the acceleration. (a) A sprinter at the very start of the race.

Select the effects of radiation below that are stochastic: associated with short-term, high-level exposure associated with long-term, low-level exposure include cancer and other DNA mutation include burns and radiation sickness

On the modern periodic table, elements are ordered according to what?

Jack drops a stone from rest off of the top of a bridge that is 24.4 m above the ground. After the stone falls 6.6 m, Jill throws a second stone straight down. Both rocks hit the water at the exact same time.

How is Electric current able to flow?