Which of the following causes seasons on Earth?
a. Earth being closer to the Sun during our summer and farther during our winter
b. the Sun's varying light output
c. the tilt of Earth's axis
d. the eleven-year sunspot cycle
c
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Vector = 4.00 m points eastward and vector = 3.00 m points southward. The resultant vector + is given by
A) 5.00 m at an angle 36.9° south of east. B) 5.00 m at an angle 53.1° south of east. C) 5.00 m at an angle 71.6° south of east. D) 5.00 m at an angle 18.4° south of east. E) 5.00 m at an angle 26.6° south of east.
A car moving at 10.0 m/s encounters a bump that has a circular cross-section with a radius of 30.0 m. What is the normal force exerted by the seat of the car on a 60.0-kg passenger when the car is at the top of the bump?
A) 200 N B) 389 N C) 789 N D) 489 N E) 589 N
An airplane travels 80 m/s as it makes a horizontal circular turn which has a 0.80-km radius. What is the magnitude of the resultant force on the 75-kg pilot of this airplane?
a. 0.69 kN b. 0.63 kN c. 0.66 kN d. 0.60 kN e. 0.57 kN
If the distance from a point source of EM radiation is doubled, the intensity is
A. doubled B. the same as it was before. C. reduced by a factor of four. D. increased by a factor of four. E. cut in half.