If a radioactive material has a half-life of 15 y what fraction of the material will remain after 30 y

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

You are in IMC and have two-way radio communications failure. If you do not exercise emergency authority, what procedure are you expected to follow?

You drop a ball from rest and simultaneously shoot a second, identical ball horizontally from the same height as the first ball. If there is no air resistance, which ball hits the ground first?

The sum of the digits of a two-digit number is 6. When the digits are reversed, the number decreases by 18. Find the original number.

If Earth's axis were tilted by 5° instead of its actual tilt, how would the seasons be different than they are currently?

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

A swimmer is swimming to the left with a speed of 1.0 m/s when she starts to speed up with constant acceleration. The swimmer reaches a final speed of 2.5 m/s over a distance of 5.0 m. How long did the swimmer take to speed up to 2.