In which situation is no work considered to be done by a force?

a. when the angle is between the force and displacement is 180

b. when the angle is between the force and displacement is 90

c. when the angle is between the force and displacement is 45

d. when the angle is between the force and displacement is 0

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.

What is the name for the remnant of an asymptotic giant that has lost its shells? black dwarf white dwarf yellow giant black hole

If the textbook weighs 19.6 newtons on venus,what is the strength of gravity on venus?