A biker is traveling at a speed of 15 m/s. Their keys drop out of their pocket without them noticing from a height of 0.8 m. What is the horizontal component of the key's velocity just before hitting the ground? (Hint: Think about what we know about an object's horizontal velocity in free fall.)

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

Which statement is true? a. kepler's laws apply only to the motion of earth. b. kepler's laws can be used to predict eclipses. c. kepler's laws are true for a central force that is directly proportional to distance. d. kepler's laws can be deduced from newton's laws of motion and gravity.

What changes occur in the brain during the teenage years? 25 points, someone me out!a.) thinking becomes slower as the brain grows larger. b.) connections between neurons become stronger and faster. c.) unused neurons fuse together to form larger, better functioning neurons. d.) more neurons are developed.