Two bodies A and B are connected by a string over a pulley and a disc slides over the string (see the figure). Then (B+D) cannot be treated as a system. The reason is[ ]
a) The distance covered by B and D are equal
b) The distance covered by B and D are not equal
c) The directions of B and D are same
d) The directions of B and D are not same

Which surface feature of the moon is characterized by mountainous areas? terrae craters maria regolith

Athermometer is removed from a room where the temperature is 70° f and is taken outside, where the air temperature is 10° f. after one-half minute the thermometer reads 60° f. what is the reading of the thermometer at t = 1 min? (round your answer to two decimal places.) ° f how long will it take for the thermometer to reach 30° f? (round your answer to two decimal places.)

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. this process was repeated by 3 observers. the pooled standard deviations of these 3 data sets was 1.21. determine the true mean force using all pooled data (with a 95% probability). the result should look like this: true mean = mean +/- margin of error