Drawbridges, such as this one at the tower of london, are raised and lowered by cable systems. now consider the drawbridge illustrated below wherein the nearly horizontal brown door is centered along the vertical brick wall, the door-wall angle is α = 75 o as measured relative to the black hinge axis, the tension (magnitude) in each cable is t = 400 n and the relevant dimensions are a = 360 cm, b = 140 cm, c = 550 cm and d = 310 cm. determine the resultant torque (magnitude) | ( m r ) a x i s | in nm that the two cables contribute to the moment about the hinge axis.

probably not if net force is zero

chemical energy --> gravitational potential energy --> kinetic energy --> elastic potential energy --> gravitational potential energy

explanation:

when emma starts the hike, the chemical energy stored in her body is used to climb up the mountain, and so she gains gravitational potential energy (because at the end, she will be at a higher height h above the ground). then she goes bungee jumping: as she falls, this gravitational potential energy is converted into kinetic energy (because her speed increases as she falls down), until the point when the rope stretches, and she stops moving. at that moment, all the kinetic energy is converted into elastic potential energy due to the stretching of the rope. then, this energy is released because the rope returns to its natural length, and emma gains a small increase in altitude , so she gains some gravitational potential energy.