The hall effect can be used to calculate the charge-carrier number density in a conductor. if a conductor carrying a current of 2.0 a is 0.5 mm thick, and the hall effect voltage is 4.5 µv when it is in a uniform magnetic field of 1.2 t, what is the density of charge carriers in the conductor?

Scientists use laser range-finding to measure the distance to the moon with great accuracy. a brief laser pulse is fired at the moon, then the time interval is measured until the "echo" is seen by a telescope. a laser beam spreads out as it travels because it diffracts through a circular exit as it leaves the laser. in order for the reflected light to be bright enough to detect, the laser spot on the moon must be no more than 1.0 km in diameter. staying within this diameter is accomplished by using a special large-diameter laser. part a if λ = 540nm , what is the minimum diameter of the circular opening from which the laser beam emerges? the earth-moon distance is 384,000 km. express your answer to two significant figures and include the appropriate units.

Describe different biomes. what are some adaptations that organisms (plants or animals) must have to live in each biome?

A10 kg box initially at rest is pulled 18 meters across a horizontal, frictionless surface by a 40 n force. what is the block’s final velocity over the 18 meters?