Xác định ứng lực trong các thanh BC, CF và FE của hệ giàn và chỉ rõ các thanh
chịu kéo hay nén. Cho P1=P2=600 lb,
P3=800 lb

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.

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz.

Holes drilled several kilometers into earth’s crust provide direct evidence about earth’s interior in the form of