Description
12. Which of these objects has the greatest inertia?
13. Which type of force can act through empty space?
14. https://tcan4424-oakcliff-ccl.gradpoint.com/Resour...
Workers are trying to free an SUV stuck in the mud. To move the vehicle, they use three ropes held parallel to the ground, producing the force vectors shown in the figure. What is the magnitude and direction of the resultant force of the three pulls?
Explanation & Answer
The law of inertia (Newton's First Law of Motion) says (in short) that a body at rest tends to stay at rest, and a body in motion tends to stay in motion, unless acted upon by an unbalanced force.
Looking at your possibilities, we should ask the following question: How hard will it be for us to change the motion (or lack of it) in each of these objects?
If a woman is running at a constant speed on a track (d), her speed could be altered by a slight gust of wind.
Ditto for a baseball in flight (b).
A computer on a desk (c) would require a pretty good shove to get it to change its resting state, right?
A parked car (a), though, would require a mighty effort--maybe from several people or another vehicle to get it to move. That's inertia.
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