Un cubo de Al de 2cm de longitud por lado tiene una masa de 21 g cual es su densidad y cual sera la masa de 5.5cm/3 ​

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.

Multiply or divide to make this english distance conversion. 174 inches = feet (14.5, 58, 2,088, 23)

Which of the following statement is false ? a. batteries should never be stored on metal trays or outside in the elements)b, battery acid cannot be neutralized)c. do not stack batteries on top of each other)d. never put a damaged battery in a dumpster. i