Q: When you turn on an electric motor, it takes longer to
When you turn on an electric motor, it takes longer to come up to final speed if a grinding wheel is attached to the shaft. Why?
See AnswerQ: You can probably stand flatfooted on the floor and then rise up
You can probably stand flatfooted on the floor and then rise up and balance on your tiptoes. Why are you unable do it if your toes are touching the wall of your room? (Try it!)
See AnswerQ: A valued client brings a treasured ball to your engineering firm,
A valued client brings a treasured ball to your engineering firm, wanting to know whether the ball is solid or hollow. He has tried tapping on it, but that has given insufficient information. Design a...
See AnswerQ: An object consists of a ball of weight W glued to the
An object consists of a ball of weight W glued to the end of a uniform bar also of weight W. If you release it from rest, with the bar horizontal, what will its behavior be as it falls if air resistan...
See AnswerQ: Suppose that the object in Question 11.9 is released from
Suppose that the object in Question 11.9 is released from rest with the bar tilted at 60° above the horizontal with the ball at the upper end. As it is falling, will it (a) rotate about its center of...
See AnswerQ: The force of gravity acts on the baton in Fig. 10
The force of gravity acts on the baton in Fig. 10.11, and forces produce torques that cause a body’s angular velocity to change. Why, then, is the angular velocity of the baton in th...
See AnswerQ: In pioneer days, when a Conestoga wagon was stuck in the
In pioneer days, when a Conestoga wagon was stuck in the mud, people would grasp the wheel spokes and try to turn the wheels, rather than simply pushing the wagon. Why?
See AnswerQ: The mighty Zimbo claims to have leg muscles so strong that he
The mighty Zimbo claims to have leg muscles so strong that he can stand flat on his feet and lean forward to pick up an apple on the floor with his teeth. Should you pay to see him perform, or do you...
See AnswerQ: An old question is “Which weighs more, a pound of
An old question is “Which weighs more, a pound of feathers or a pound of lead?” If the weight in pounds is the gravitational force, will a pound of feathers balance a pound of lead on opposite pans of...
See AnswerQ: Why is it easier to hold a 10-kg dumbbell in
Why is it easier to hold a 10-kg dumbbell in your hand at your side than it is to hold it with your arm extended horizontally?
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