Which statement best describes why warm ocean currents are usually surface currents?

a) warm water is less dense than cold water.
b) ocean tides bring warm water to the surface.
c) warm water contains more salt than cold water.
d) ocean water loses heat to the air at the surface.

Abaseball picther can throw a ball at about 90 miles per hour, v = 40 m/s, on solid rock ground. we now put him into space. when he throws the ball, which weighs mb = 0.15 kg moves away from himat the same speed. how long does it take the ball thrown in space to travel the 30 meters to the batter? he weighs mp = 100kg

In order for the bug to fly through the air a force has to push the bug forward. identify this force. how does the bug produce

You throw a small rock straight up from the edge of a highway bridge that crosses a river. the rock passes you on its way down, 7.00 s after it was thrown. what is the speed of the rock just before it reaches the water 28.0 m below the point where the rock left your hand? ignore air resistance.