Work = force x distance. In units, Joules = Newtons x meters.
So: Work = 50 Newtons x 3 meters
Work = 150 joules. Answer D is correct
FYI - to ace physics, you should learn to identify these values using their fundamental units:
Force = Newtons = Kg·m/s²
Work = joules = kg·m²/s²
Power = watts = kg·m²/s³
In high school physics, If you learn to arrange equations so the units work out properly for the answer, you'll get most problems correct.
The mass of a radioactive element at time t is given by

where

is the mass at time zero, while

is the half-life of the element.
In our problem,

, t=121.0 s and

, so we can find the initial mass

:
With utmost clarity, that is truest of the truths
Answer:
Wind the long piece of thin wire around the uniform glass rod multiple times, find the length of the total diameters using the metre ruler, and divide by the number of times you wound it around the rod.
Explanation:
Since the diameter of one long piece of thin wire is too thin to be measured by a metre ruler, you can wind it multiple times and push it side by side to get a length you can measure.
For example, if you wound it around 20 times and the total length of 20 diameters of the wire side-by-side is 2.0 cm, one winding, which is the diameter would be 2.0cm ÷ 20 = 0.10cm or 1mm.
Information I learned from history class Education in the 1950's expanded from previous decades. They no longer focused purely on reading, writing and arithmetic. History and science became a main part of the cirriculum. Also, enrollment skyrocketed as the baby-boomers began enrolling in elementary school. One interesting thing that categorized this generation was the presence of fallout tests. Schools would require the students to go through a fake atomic bomb attack in which they would hide under their desks (which was completely pointless in protecting them from radiation, it was more of an emotional security for the parents and teachers, but scared the hell out of the students). Socially, children were taught to conform and to be normal. Standing out or questioning authority was bad. Sex was taught, though minimally. They explained the penis and vagina. Sexually transmitted diseases were focused on greatly so as to "scare" the students out of premarital sex.