An amusement park ride consists of a rotating
circular platform 7.89 m in diameter from
which 10 kg seats are suspended at the end
of 3.49 m massless chains. when the system
rotates, the chains make an angle of 34.4
◦ with
the vertical.
the acceleration of gravity is 9.8 m/s

what is the speed of each seat?
answer in units of m/s

a car accelerates uniformly from rest and
reaches a speed of 34.8 m/s in 12.4 s. the
diameter of a tire is 92.6 cm.
find the number of revolutions the tire
makes during this motion, assuming no slipping.
answer in units of rev.

Antireflective coatings on solar cells are often made by applying a thin film of silicon nitride (sinx), which has an index of refractive of 1.2, on the top of the silicon solar cell, which has a refractive index of about 3.5. however, the sun emits radiation of various wavelengths which the solar cell absorbs, and the antireflective coating can only absolutely minimize the reflection of one of these wavelengths. the coating thickness is chosen to reduce the reflection of green/yellow light (e = 2.2 ev), which is the most intense color in the solar spectrum (shown below). which of the following coatings would minimize reflection of green/yellow light? the answer is 820 nm how? what is the angular width of the central maximum of an electron traveling at 2 x 108 m/s going through a single slit of width 1 mm.

Abird flies directly overhead from where you stand at an altitude of 300.0 m and at a speed horizontal to the ground of 20.0 m/s. the bird has a mass of 2.0 kg. the radius vector to the bird makes an angle \thetaθ with respect to the ground. the radius vector to the bird and its momentum vector lie in the xyxy-plane. what is the bird’s angular momentum about the point where you are standing?

Is the portion of the electromagnetic spectrum that has a frequency just above that of visible light.