Q: A bird is flying due east. Its distance from a tall
A bird is flying due east. Its distance from a tall building is given by x(t)= 28.0 m +(12.4 m/s)t –(0.0450 m/s3)t3. What is the instantaneous velocity of the bird when t = 8.00 s?
See AnswerQ: A ball moves in a straight line (the x-axis
A ball moves in a straight line (the x-axis). The graph in Fig. E2.9 shows this ball’s velocity as a function of time. (a) What are the ball’s average speed and ave...
See AnswerQ: A squirrel has x- and y-coordinates (1.
A squirrel has x- and y-coordinates (1.1 m, 3.4 m) at time t1 = 0 and coordinates (5.3 m, -0.5 m) at time t2 = 3.0 s. For this time interval, find (a) the components of the average velocity, and (b) t...
See AnswerQ: A daring 510-N swimmer dives off a cliff with a
A daring 510-N swimmer dives off a cliff with a running horizontal leap, as shown in Fig. E3.10. What must her minimum speed be just as she leaves the top of the cliff so that she will miss the ledge...
See AnswerQ: Crickets Chirpy and Milada jump from the top of a vertical cliff
Crickets Chirpy and Milada jump from the top of a vertical cliff. Chirpy drops downward and reaches the ground in 2.70 s, while Milada jumps horizontally with an initial speed of 95.0 cm/s. How far fr...
See AnswerQ: A rookie quarterback throws a football with an initial upward velocity component
A rookie quarterback throws a football with an initial upward velocity component of 12.0 m>s and a horizontal velocity component of 20.0 m/s. Ignore air resistance. (a) How much time is required for t...
See AnswerQ: In the conical pendulum of Example 5.20 (Section 5
In the conical pendulum of Example 5.20 (Section 5.4), which of the forces do work on the bob while it is swinging? Example 5.20: An inventor designs a pendulum clock using a bob with mass m at the...
See AnswerQ: A curve in a road has a bank angle calculated and posted
A curve in a road has a bank angle calculated and posted for 80 km/h. However, the road is covered with ice, so you cautiously plan to drive slower than this limit. What might happen to your car? Why?...
See AnswerQ: A mass m slides down a smooth inclined plane from an initial
A mass m slides down a smooth inclined plane from an initial vertical height h, making an angle a with the horizontal. (a) The work done by a force is the sum of the work done by the components of the...
See AnswerQ: A 12-pack of Omni-Cola (mass 4.
A 12-pack of Omni-Cola (mass 4.30 kg) is initially at rest on a horizontal floor. It is then pushed in a straight line for 1.20 m by a trained dog that exerts a horizontal force with magnitude 36.0 N....
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