An empty car on a steep street rolls downhill and collides with a concrete wall. The car is damaged, but the concrete wall isn’t. What’s true about the strength of the forces in this situation? A. The force on the car was greater because it was moving
B. The force on the wall was greater because it wasn't damaged
C. The forces exerted by the car and wall were equal
D. No forces were exerted in this collision because the car was empty

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?