Which statement is true about using shorter, steeper inclined planes to lift an object? A. Fewer lifters are needed, and it will take more time.
B. Fewer lifters are needed, and it will take less time.
C. More lifters are needed, and it will take more time.
D. More lifters are needed, and it will take less time.

Estimate the kinetic energy of mars with respect to the sun as the sum of two terms, that due to its daily rotation about its axis, and that due to its yearly revolution about the sun. (assume mars is a uniform sphere with mass = 6.4×10 to the power of 23 kg, radius = 3.4×10 to the power of 6 m, rotation period = 24.7 hours, orbital period = 686 days and is 2.3×10 to the power of 8 km from the sun.)