A sample of fluorine-18 in a laboratory has an initial mass of 50mg. flourine-18 has a half life of 1.8 hours Calculate the amount of time it will take for the initial mass of fluorine-18 to be reduced from 59 mg to 12.5mg

A uniform diameter rod is weighted at end and is floating in a liquid. Determine if the liquid is (a) lighter than water, (b) water, or (c) heavier than water. Justify your answer.

What is a longitudinal wave?

Which term best describes the movement of waves and how they interact with one another? a. wave shape b. wave velocity c. wave behavior d. wave chemistry

How many protons does carbon have?

Which of the following is not one of the main five types of reactions?

Wright true or false: 1. A baseball has more momentum than a tennis ball traveling at the same speed. 2. A light ball has more inertia than a heavy ball 3. The less momentum a bowling ball has, the easier it is for that ball to knock down pins. 4.

The interference of two sound waves of slightly different frequencies produces

8. A force of 80 pounds on a rope is used to pull a box up a ramp inclined at 100 from the horizontal. The rope forms an angle of 330 with the horizontal. How much work is done pulling the box 25 feet along the ramp?

A raindrop has a mass of 5.4 * 10-7 kg and is falling near the surface of the earth. Calculate the magnitude of the gravitational force exerted (a) on the raindrop by the earth and (b) on the earth by the raindrop.

As an astronaut travels towards Earth, her weight A. decreases because gravity decreases. B. decreases because her mass decreases. C. increases because gravity increases. D. remains the same because her mass remains the same.