Thousands of years ago, giraffes with short necks were common within giraffe populations. Nearly all giraffe populations today have long necks. This difference could be due to

3. A spring loaded gun fires a bullet into a block of wood hanging from a frictionless pendulum. a. How fast was the bullet going when it left the gun? Spring: k = 5,000 N/m Bullet: m=20.0g Block of wood: m = 1.00kg b.

When a 20 V battery is hooked up to a 100 Ω resistor in a circuit, how much current flows through the circuit?

What early advance first increased the ability to communicate over long distances?

A construction worker is carrying a load of 40 kilograms over his head and is walking at a constant velocity. If he travels a distance of 50 meters, how much work is being done?

Acceleration is best described as the rate of change in?

Mazie stands on her kitchen floor. The coefficient of kinetic friction between her socks and the floor is 0.62, and the coefficient of static friction is 0.75. She has a mass of 42 kg. a.

The kinetic energy of an object is quadrupled. its momentum will change by what factor?

Combining which of the following substances with germanium will cause the germanium to emit free electrons? A. Bismuth B. Gallium C. Aluminum D. Indium

A 50.0-g Super Ball traveling at 25.0 m/s bounces off a brick wall and rebounds at 22.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.

A heat engine with a thermal efficiency of 45 percent rejects 500 kj/kg of heat. how much heat does it receive