Asphere of uniform density with mass 21 kg and radius 0.8 m is spinning, making one complete revolution every 0.8 s. the center of mass of the sphere has a speed of 8 m/s. (a) what is the rotational kinetic energy of the sphere?

The mass of the sun is 1.99×1030kg and its distance to the earth is 1.50×1011m. what is the gravitational force of the sun on the earth?

Calculate the numbers of photons having a wavelength of 10.0 mm required to produce 1.0 kj of energycalculate the numbers of photons having a wavelength of 10.0 mm required to produce 1.0 kj of energy

An electron and a proton are held on an x axis, with the electron at x = + 1.000 m and the proton at x = - 1.000 m. part a how much work is required to bring an additional electron from infinity to the origin? express your answer with the appropriate units. part b if, instead of the second electron coming in from infinity, it is initially at x = + 20.00 m on the axis and is given an initial velocity of 100.0 m/s toward the origin, does it reach the origin? part c how close to the origin does it come?