Alight spring has a force constant of 70 n/m and is used to pull a 10 kg box on a horizontal frictionless surface. if the box has an acceleration of 5
m/s2, by how much does the spring stretch if it pulls on the sled at 30.0° above the horizontal?
88.9 cm
50.7 cm
82.4 cm
66.3 cm

Which simple machine is not part of this compound machine? a. lever b. pulley c. inclined plane d. wheel and axle

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.

The charge on an electron is 1.60218 × 10−19 c and its mass is 9.10939 × 10−31 kg. how strong a magnetic field must be experienced by the electron if its path is a circle of radius 5.5 cm? answer in units of t.