Which example provides a complete scientific description of an object in motion? the vibration of the jackhammer broke through the south-facing rock in under 10 seconds. the hockey player sent the puck flying toward the north goal to score the winning point. the tiger had to run at 50 kilometers for hour across the field to catch the zebra. the hiker followed the north trail a distance of two kilometers in thirty minutes.

In this experiment, you will use a track, a toy car, and some washers to explore newton’s first two laws of motion. you will make observations and collect data regarding the motion of these objects. in the space below, write a general scientific question that you will answer by doing this experiment.

The earth remains in orbit around the sun due to the force of gravity. how does the force of gravity exerted by the sun on the earth compare to the force of gravity exerted by the earth on the sun?

Aroll in a paper machine is powered by a separately excited dc machine. operating point 1 (under load): the roll typically operates at 764 rpm and must provide 301 nm of torque to oppose the load of the paper. the armature voltage is 230v for this operating point operating point 2 (no load): when the load is removed the speed of the roll increases to 900 rpm (the field characteristics are unchanged) la ea dev m (a) calculate the maximum torque (units of nm) that the motor can supply with this applied voltage (b) calculate the value of the armature resistance, ra (in ohms) (c) at operating point 1 (loaded condition), the field current, i, and the total input power (armature field), are measured to be to be 10 a and 28,600 w respectively. use this information to calculate the value of the field resistance, rf (in ohms). (d) (d) at operating point 1 (loaded condition), calculate the motor efficiency. express your answer as a percent to at least 2 significant digits. (d) if the field voltage is reduced by 1/2, calculate the new stall torque (in nm) of the motor (f). if the field voltage is reduced by 1/2, calculate the new no-load speed (in rad/sec)