How can it be so hard to drag rubber across smooth glass if friction is caused by surface roughness?​

Identify the amplitude on the diagram and give the correct description. question 3 options: a because amplitude is the distance from wave crest to wave crest. b because the wavelength shows amplitude. c because amplitude is the distance between a crest (or trough) and rest. d because wavelength show amplitude. (brainiest if you get it right! ) ~kayla

The roller coaster from problem #1 then tops a second hill at 15.0 m/s, how high is the second hill? 91.5 m 79.2 m 80.0 m 68.5 m

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.