Dolphins can use sonar to detect objects in the sea. How far away is the object from the dolphin if the sonar takes 1 sec to be returned? Sound travels at 1484 m/s in sea water.

Bone-strengthening physical activity done increases bone-mineral content and bone density in youth.

Two polarizers are oriented at 40∘ to each other and plane-polarized light is incident on them. if only 16 percent of the light gets through both of them, what was the initial polarization direction of the incident light?

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?