Solutions to Speed section exercises
Dr. Cruzan‛s Math & Science Web
© 2013, J. Cruzan
1. If a race car completes a 3-mile oval lap in 58 seconds, calculate its average speed
in mi./h. Did the car accelerate during the 58 seconds?
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2. The Moon orbits Earth in a near-circular (elliptical) orbit of radius 3.84 x 10 m
in 27.3 days. Calculate the average speed of the moon in its orbit.
3. The diameter of Earth is about 12,800 Km. It takes Earth 24 h to rotate once on
its axis. Calculate the average speed of any object on the surface of the Earth at
the equator. Convert to mi./h, too.
4. The typical airborne speed of an intercontinental B747 jet is 530 mi./h, while the
speed of the supersonic (faster than sound) Concorde was 1500 mi./h. If each
airliner were to circumnavigate Earth (25,000 mi.) what would be the difference
in air time spend by the two aircraft?
Solutions to Speed section exercises (page 2 of 2)
Dr. Cruzan‛s Math & Science Web
© 2013, J. Cruzan
5. It takes light (speed = 3.0 x 108 m·s-1) 8.33 min. to travel from the Sun to Earth,
and 1.3 seconds from the moon to Earth. Calculate the average distances of the
Sun and Moon from Earth.