Water accelerated by a nozzle to 20 m/s strikes the vertical back surface of a cart moving horizontally at a constant velocity of 5 m/s in the flow direction. the mass flow rate of water through the stationary nozzle is 30 kg/s. after the strike, the water stream splatters off in all directions in plane of the back surface. (a) determine the force that needs to be applied by the breaks of the cart to prevent it from accelerating. (b) if this force were used to generate power instead of wasting it on the breaks, determine the maximum amount of power that could be ideally generated.

An object is dropped from a tower, 400 ft above the ground. the object's height above ground t seconds after the fall is s(t)equals400 minus 16 t squared. determine the velocity and acceleration of the object the moment it reaches the ground. the velocity of the object the moment it reaches the ground is nothing ft/s.

Aparticle of mass m is projected with an initial velocity v0 in a direction making an angle α with the horizontal level ground as shown in the figure. the motion of the particle occurs under a uniform gravitational field g pointing downward. (a) write down the lagrangian of the system by using the cartesian coordinates (x, y). (b) is there any cyclic coordinate(s). if so, interpret it (them) physically. (c) find the euler-lagrange equations. find at least one constant of motion. (d) solve the differential equation in part (c) and obtain x and y coordinates of the projectile as a function of time. (e) construct the hamiltonian of the system, h, and write down the hamilton’s equations (canonical equations) of motion.

Which is not an example of how an object gains elastic potential energy by stretching? a. jumping on a pogo stick b. pulling on a rubber band c. jumping on a trampoline