How o astronomers gather information to establish the hubble law?

Give the reason why all atoms have total charge of zero

Define the efficiency of an energy converter.

Which of these best explains why Earth's tectonic plates move? Convection currents in the asthenosphere make fluid particles move. Cooling causes contraction and shifting of the fluid particles in the lithosphere.

Suppose I create a two-slit interference pattern using light with some wavelength lambda and slits with some separation D.

When the net force on an object is greater than 0, how is its related to its acceleration

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.