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

An object with an initial velocity of 3.0 m/s has a constant acceleration of 2.0 m/s2. When its speed is 19.0 m/s, how far has it traveled?

What does a trench form? What happens here?

Electricity from the local power company costs 7.22 cents/kWh. A homeowner wishes to pay a maximum of 25 cents per month for the electricity to power a stereo system. For how many hours per month could the stereo system be used?

Which has the greater density, a lake full of water or a cup full of lake water?

What is a solution? A. One substance dissolved in another substance B. A pure substance by itself C. One liquid layered on another liquid D. Two substances chemically bonded together

An example of objects the move in revolution

How many hops does a kangoroo do in 1 day

What are the average velocity and average acceleration of the tip of a 2.4 cm long hour hand of a clock?

What is the number one and most important rule to remember in soccer?

Why are convection currents; why are they hotter and colder parts of earth