A rotary encoder is connected directly to the spindle of a machine tool to measure its rotational speed. The encoder generates 144 pulses for each revolution of the spindle. In one reading, the encoder generated 267 pulses in a period of 0.25 sec. What was the rotational speed of the spindle in (a) rev/min

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.

answerscientific theory;

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle