Select the correct answer. A pair of pliers is an example of a simple machine with two levers. Which part of the pliers is the fulcrum?

A. A
B. B
C. C
D. D
E. E

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.

Crowbar of 5 metre is used to lift an object of 800 metre if the effort arm is 200cm calculate the force applied

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?