A student claims that all objects exert a gravitational force on one another. However, it is difficult to observe the effect of the force of gravity unless the mass of one of the objects is very large. Which
observation best supports the student's argument?
A. Earth spins on its axis at a constant speed.
B. The masses of the Moon and Earth are constant.
C. The Moon stays in orbit around Earth.
D. The solar system has moons of different masses.

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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.

Crowbar of 5 metre is used to lift an object of 800 metre if the effort arm is 200cm calculate the force applied

If a spring has a k value of 100 newtons per meter and it is stretched 0.50 meters, what is the restoring force of the spring?