Cobalt-60 has a half life of 5.25 years. If you started with a 40 gram sample of pure cobalt-60, how many grams of cobalt-60 would remain after 10.5 years?

Why does the moon cycle from new moon to full moon?

The fastest land animal is the cheetah which can run about 70 miles an hour the fact that its main prey species the thomson's gazelle can run about 50 miles an hour is likely the result of

A wheelbarrow is an example of what type of lever

At the surface of the ocean, the water pressure is the same as the air pressure abovethe water, 15 lb/in2. Below the surface, the water pressure increases by 4.34 lb/in2forevery 10 ft of descent.

A 0.065-kg tennis ball moving to the right with a speed of 15 m/s is struck by a tennis racket, causing it to move to the left with a speed of 15 m/s. if the ball remains in contact with the racquet for 0.

Does the ear drum vibrates when struck by sound waves and directly sends a message to the brain that is then recognized as sound?

Think of an example that you could use to convice a friend that an object at rest has an "internal hold back property" that is different from a frictional force or the force of the earth's gravity.

Sally places a jar with some pennies into a pool of water and exactly half of the jar is submerged. The volume of the jar is 200 cm3 and the density of the water is 1 g/cm3. a. What is the buoyant force acting on the jar? b.

According to the law of reflection the angle of incidence is equal to the angle of blank

Sound travels 2146 m through a material in 1.4 seconds. What is the material?