Clocking a meter with a two-foot dial for 45 seconds yields which reading?

Clocking a meter with a two-foot dial for 45 seconds yields which reading?

• A. 120
• B. 160
• C. 180
• D. 200

Answer: (B)

Clocking a meter measures how fast the dial accumulates units by timing its movement. The reading after a fixed interval is simply the rate of the dial’s increase multiplied by the elapsed time. Here, after 45 seconds the dial shows 160 units, which means the rate is 160 divided by 45, about 3.56 units per second. Multiply that rate by 45 seconds and you get 160, so the reading is 160. The other numbers would require a different rate or a different timing interval.

Clocking a meter measures how fast the dial accumulates units by timing its movement. The reading after a fixed interval is simply the rate of the dial’s increase multiplied by the elapsed time. Here, after 45 seconds the dial shows 160 units, which means the rate is 160 divided by 45, about 3.56 units per second. Multiply that rate by 45 seconds and you get 160, so the reading is 160. The other numbers would require a different rate or a different timing interval.