What's heavier a pound of feathers or a pound of stones?

An observer in the Earth reference frame observes cart A and cart B moving toward each other with the same speed until they collide and come to rest. Consider this event as seen by observer A moving along with cart A.

A river has a current with a velocity of 10km/hr south. A boat traveling with the current has a speed of 25 km/hr. What is the resulting velocity of the boat?

How much heat is absorbed by a 61g iron skillet when its temperature rises from 5oC to 29oC?

Which of the 7 Physical Fitness Components would describe long distance running? 20 pts

Describe what determines whether an object is part of our solar system

Does the sun fuse hydrogen into helium or vice versa?

Is it possible to put a distance versus time graph to be universal go mine

On very dry days, when you use a comb or a brush, your hair sometimes stands on the end and maybe even sticks to the comb or brush. Explain why this happens in terms of electric charge.

A large balloon is initially filled to a volume of 1.96 l at 318.44 k and a pressure of 2.89 atm. what volume of gas will the balloon contain at 1.77 atm and 336.33 k?

How to calculate kinetic energy? (physics/physical science)