2. where do you find the electrons in an atom?
a. in the nucleus
b. travelling around the nucleus
c. in the protons
d. travelling in the protons

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.

If an object with an initial temperature of 300 k increases its temperature by 1°c every minute, by how many degrees fahrenheit will its temperature have increased in 10 minutes? (a) 6°f (b) 10°f (c) 18°f (d) 30°f

If the spring constant k of a pogo stick is 3500 n m and the weight of the person on the pogo stick is 700 n, how much is the spring in the botom of the pogo stick compressed?