No force is necessary to a. start an object moving.
b. stop an object from moving.
c. cause a change in the motion of an object.
d. keep an object doing what it is already doing.

Ogle–2013–blg–0723 is an exoplanet that is similar to earth in size and proximity to its star. this exoplanet has mass m=4.18×1024kg and radius r=5.66×106m. an astronaut whose weight on earth is w=735n lands on the planet. a. calculate m, the mass of the astronaut. b. calculate gp? , the acceleration due to gravity on the surface of ogle–2013–blg–0723. c. calculate wp? , the weight of the astronaut on the surface of ogle–2013–blg–0723. d. calculate v, the minimum velocity required to put an object into orbit above ogle–2013–blg–0723. e. calculate t, the time required to complete an orbit around ogle–2013–blg–0723.

The difference between a red shift and a blue shift has to do with wavelength frequency. t or f

Gordon is going for a run through the park, but it is cold outside. the low outside temperature could affect his personal safety.