8. Semiconductors

A) do not obey Ohm's law

B) obey Ohm's law

C) do not use electrons to conduct electricity.

D) need light to work

A car accelerates from rest to 24m/s in 8s. what is it's average speed?

The spans of time that make up the Earth's geologic timescale are generally defined by the different types of

Old cannons were built on wheeled carts, both to facilitate moving the canon and to allow the canon to recoil when fired. When a 200 kg canon in car recoils at 1.7 m/s, at what velocity would a 10 kg cannonball leave the Cannon?

1. Hydrogen gas and oxygen gas, when combined, form liquid water. What type of change is this, and why? A) Chemical change, because a gas is produced. B) Physical change, because it is changing from gas to liquid.

A 6.0 kg bucket of water is raised from a well by a rope. if the upward acceleration of the bucket is 3.9 m/s2, find the force exerted by the rope on the bucket

Tom stops using a new skin cream for five days to determine if the cream is the cause of a recent rash. What stage of the scientific method is Tom using?

Use your observations to determine qualitatively how the strength of the electric interaction between charged objects depends on the distance between them. Explain your reasoning (this is trickier than it might seem at first).

Far from any other masses, two masses, m1 and m2, are interacting gravitationally. The value for the mass of m1 suddenly doubles. What happens to the value of the gravitational force that mass m2 exerts on mass m1?

Which of the outer planets are most like Earth? How?

The pressure inside a champagne bottle can be quite high and can launch a cork explosively. Suppose you open a bottle at sea level. The absolute pressure inside a champagne bottle is 6 times atmospheric pressure; the cork has a mass of 7.