Fluorine-21 has a half-life of approximately 5 seconds. What percentage of the original nuclei would remain after 20 seconds

A wildlife researcher is tracking a flock of geese. the geese fly 3.5 km due west, then turn toward the north by 40 ∘ and fly another 4.5 km, what is the magnitude of their displacement

2. If the efficiency of a device is 64 %, what is the amount of Energy lost / wasted by this device? Explain

Stephen can push with 200N of force on a couch. if the couch has a mass of 20 kg, how much acceleration will the couch have? the answers: 4,000 m/s/s, 100 m/s/s, 10 m/s/s, 180 m/s/s.

When the same masses are heated by the same amount, which of the following substances will heat up the slowest? -aluminum ... 0.90 -iron ... 0.46 -gold ... 0.13 -copper ... 0.39

Does a liquid give off energy or absorb energy when it turns into a gas? when it turns into a solid?

Why does Mars have moons even when its mass is small?

During the forging process for a steel sword, the blacksmith places a hot iron blank into a cold bucket of water. Which of the following happens? A. The water molecules move faster. B. The steel molecules move faster. C.

If you are trying to balance a seesaw and you have a higher mass on the left, should the mass on the right be placed at a greater distance or lower distance to balance it? Why?

What are copper atoms held together by

Which of the following are the top two job expectations of people who career plan? Select all that apply. A. Hours B. benefits C. type of work D. coworkers E. security