Why does the earth have a magnetic field?

Gravity affects mass. The higher the gravity, the more mass an object will have. True False

A geologist finds ripples preserved in ancient sedimentary rock that look just like ripples made by water in mud. He concludes that there was once water in that location that created the ripples. Why is this conclusion reasonable?

How do simple machines make work easier? A. They add energy to the work. B. They increase the force needed to work. C. They reduce the speed of work. D. They increase the distance over which a force is applied.

A 150 kg hoop rolls along a horizontal floor so that the hoop's center of mass has a speed of 0.130 m/s. how much work must be done on the hoop to stop it?

For the reaction shown below, which statement is correct? Ba (OH) 2 + 8H20 + 2NH4NO3 + heat?10H2O + 2NH3 + Ba (NO3) 2 A. The products contain more energy. B. The reactants contain more energy. C.

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.