The energy needed to get a reaction started is the

A. adhesion energy.

B. activation energy.

C. cohesion energy.

D. chemical energy.

A student determined to test the law of gravity for himself walks off a skyscraper 900 ft high, stopwatch in hand, and starts his free fall (zero initial velocity).

The storm waves are about 2 meters high and about 35 meters apart. What properties of waves is this?

A low-velocity flow over a smooth stream bed produces a

If the average pitcher is releasing the ball from a height of 1.8 m above the ground, and the pitcher's mound is 0.

A soccer player is running upfield at 10m/s and comes to a stop in 3 seconds facing the same direction. What is his acceleration

What is a circuit, s resistance if 12v produces 2A of current?

Dinosaur fossils are too old to be reliably dated using carbon-14, which has a half-life of about 5730 years. Suppose we had a 68 million year old dinosaur fossil.

A power station delivers 510 kw of power at 12,000 v to a factory through wires of total resistance of 2.5 ω. how much less power is wasted if the electricity is delivered at 47,000 v rather than 12,000 v?

Two spaceships of mass 300,000 kg are 250 m apart. what is the force of gravity between them? (G = 6.67 times 10⁻¹¹ N*M²/kg²)

Air pressure is 1.0 · 105 N/m2, air density is 1.3 kg/m3, and the density of soft drinks is 1.0 · 103 kg/m3. If one blows carefully across the top of a straw sticking up 0.