An unknown radioactive element decays into non-radioactive substances. In 100 days the radioactivity of a sample decreases by 64 percent. a)(a) What is the half-life of the element? half-life: b)How long will it take for a sample of 100 mg to decay to 51 mg? time needed:
If a number increases from 47 to 70.5 what is the rate of increase?
What is 7,000 decreased by 62%?
the mass of the oxygen (o2) in a room is 0.0568 grams. How many oxygen molecules are in the room. 2 conversions are needed.
which of these ancient civilizations survived, intact, until the twentieth century?
A dog kennel is to be constructed alongside a house using 60 m of fencing. Find the dimensions that will yield the maximum area. How do you solve this problem?
a block of aluminum is placed in 10.0g of water. the initial temperature of the water is 22.0 degrees celcious and its final temperature is 27.0 degrees celcious. what is the amount of heat released by the block of aluminum in calories if it had an initial temperature of 48.0 ...
Construct a 5th mode standing wave on a string that has an unknown mass hanging from one end. The distance between fixed ends of the string is 0.9 meters. If the wave speed on the 1.3 meter string is 216 meters per seconds and the string has a mass of 3 grams, what is the valu...
What kind of fallacy are these 2 examples? 1. "Fresh fruits and veggies make life better." 2. "Fairway coffee is the essence of life itself."
A string fixed at both ends is 9.31 m long and has a mass of 0.125 kg. It is subjected to a tension of 100.0 N and set oscillating. (a) What is the speed of the waves on the string? m/s (b) What is the longest possible wavelength for a standing wave? m (c) Give the frequency o...
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