How many half-lives have passed if a sample contains 25% of its original carbon-14? 1 half-life
2 half-lives
3 half-lives
4 half-lives

Debbie places two shopping carts in a cart corral she pushes the first cart which then pushes a second cart what force is being exerted

Afisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. it takes a time of 2.20 s for the boat to travel from its highest point to its lowest, a total distance of 0.670 m . the fisherman sees that the wave crests are spaced a horizontal distance of 5.80 m apart. (a) how much is the wavelength? (b) find the period of the wave. (c) how fast are the waves traveling? (d) what is the amplitude a of each wave?

Select all that applywhat are some basic resources a family is expected to provide for children? educationclothesspending