For a body to be equilibrium under the combined action of several forces: a. any two of these forces must be balanced by a third force the sum of the torques about
b. any point must equal zero
c. all of the forces are composed of pairs of equal and opposite forces
d. all the forces must be applied at the same point the lines of action of all
e. the forces must pass through the center of gravity of the body

The 10-kg double wheel with radius of gyration of 125mm about o is connected to the spring of stiffness k = 600 n/m by a cord which is wrapped securely around the inner hub. if the wheel is released from rest on the incline with the spring stretched 225 mm, calculate the maximum velocity v of its center o during the ensuing motion. the wheel rolls without slipping

An astronaut floating in space is trying to use her jetpack to get back to her space station, but she is being pulled away by a nearby planet, as shown in the image below. her jetpack provides a constant thrust of 310 n. if she angles her jetpack in such a way that it cancels out the vertical force due to the planet's gravity, what is her net horizontal force? thaud 487 o a. 54.8 n toward the space station o b. 212.9 n toward the space station o c. 185.2 n toward the space station o d 956 n toward the space station

A55-kg pilot flies a jet trainer in a half vertical loop of 1200-m radius so that the speed of the trainer decreases at a constant rate. knowing that the plane has a speed of 550 km/h at point a, and the pilot experiences weightlessness at point c (i. e., the normal force from the seat bottom is zero), determine (a) the deceleration of the plane, (b) the force exerted on her by the seat of the trainer when the trainer is at point b.