Name of group to which hydrogen belongs to

An old theory about the position of planets and the sun in the galaxy has been replaced by a new theory. Which of these statements is correct about the two theories? The new theory is accepted because its explanations became a law.

If a speeding train hits the brakes and it takes the train 39 seconds to go from 54.8 m/s to 12 m/s what is the acceleration?

a piece of metal with a mass of 15.3 grams has a temperature of 50.0°C. When the metal is placed in 80.2 grams of water at 21.0°C, the temperature rises by 4.3°C. What is the specific heat capacity of the metal?

How is a net electric charge produced?

Both physical feature and behaviors can be inherited True False

Two copper wires with different diameters are joined end to end. If a current flows in the wire combination, what happens to electrons when they move from the larger-diameter wire into the smaller-diameter wire?

A baseball player is warming up and tosses a ball straight up into the air. The ball travels up until it reaches some maximum height, and then falls back down to the player/'s hand.

Volume can be measured in liters or cubic meters. a. T b. F

A spring with a spring constant of 1200 N/m has a 55-g ball at its end. The energy of the system is 5.5J. What is the amplitude of vibration?

Force F1 acts on a particle and does work W1. Force F2 acts simultaneously on the particle and does work W2. The speed of the particle does not change. Which one of the following must be true? a. W1 is zero, and W2 is positiveb. W1 = - W2c.