What allows a tightrope walker to walk across the rope?
tension
air resistance
friction
magnetic force
isabella pushes a box with a force of 20 n. it accelerates at 2 m/s/s. what is the mass of the box?
10 kg
40 kg
22 kg
cannot be determined

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.)