Three-phase, 4-wire panelboards are usually constructed with an even number ofspaces available for each phase; thus, the total number of spaces would be in incre-ments of 6, such as 12, 18, 24, 30, 36, or 42. how many spaces would be available forthe later addition of circuit breakers in panelboard p-1 after the panelboard has been equipped as scheduled?

Astone is dropped from the upper observation deck of a tower, 250 m above the ground. (assume g = 9.8 m/s2.) (a) find the distance (in meters) of the stone above ground level at time t. h(t) = (b) how long does it take the stone to reach the ground? (round your answer to two decimal places.) s (c) with what velocity does it strike the ground? (round your answer to one decimal place.) m/s (d) if the stone is thrown downward with a speed of 2 m/s, how long does it take to reach the ground? (round your answer to two decimal places.) s