Box 4: Making things move Explain the relationship between the python code
force = -G*sun. M*earth. M*R/magR**3
and the equation
F⃗ = −GmSmE Rˆ . R2
Hint: starting with the vector R⃗ how can we find the unit vector Rˆ which points in the direction of R⃗? Remember that we use in python we use ** for exponentiation so that magR**3 means (magR)3.

Multiple choice. choose the one alternative that best completes the statement or answers the question. 1) if the force on an object is in the negative direction, the work it does on the object must be 1) a) negative. b) positive. c) the work could be either positive or negative, depending on the direction the object moves. 2) a truck has four times the mass of a car and is moving with twice the speed of the car. if kt and kc refer to the kinetic energies of truck and car respectively, it is correct to say that 2) a) kt = 16kc . b) kt = 1 2 kc. c) kt = kc . d) kt = 2kc . e) kt = 4kc . 3) you and your friend, who weighs the same as you, want to go to the top of the eiffel tower. your friend takes the elevator straight up. you decide to walk up the spiral stairway, taking longer to do so. compare the gravitational