Concept explainers
Animal Athletes
Different animals have very different capacities for running. A horse can maintain a top speed of 20 m/s for a long distance but has a maximum acceleration of only 6.0 m/s2, half what a good human sprinter can achieve with a block to push against. Greyhounds, dogs especially bred for feats of running, have a top speed of 17 m /s, but their acceleration is much greater than that of the horse. Greyhounds are particularly adept at turning corners at a run.
Figure 1.1
In the photograph of the greyhounds in Figure I.1, what is the direction of the net force on each dog?
A. Up
B. Down
C. Left, toward the outside of the turn
D. Right, toward the inside of the turn
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