Aball whirls around in a vertical circle at the end of a string. the other end of the string is fixed at the center of the circle. assume that the total energy of the ball-earth system remains constant.
(a) what is the tension in the string at the bottom? (use the following as necessary: m for mass of the ball, g for gravitational acceleration, vb for velocity at the bottom, andr for radius of the circle.)
tb =
(b) what is the tension in the string at the top? (use the following as necessary: m, g, vt for velocity at the top, and r.)
tt =
(c) how much greater is the tension at the bottom? (use the following as necessary: m, g.)
tb = tt +

Athin plate moves between two parallel, horizontal, stationary flat surfaces at a constant velocity of v = 7.5 m/s. the two stationary surfaces are spaced 4 cm apart, and the medium between them is filled with oil whose viscosity is 0.9 n·s/m2. the part of the plate immersed in oil at any given time is 2 m long and 0.5 m wide. if the plate moves through the mid-plane between the surfaces, determine the force required to maintain this motion. what would your response be if the plate was 1 cm from the bottom surface (h2) and 3 cm from the top surface (h1)? if the plate moves through the mid-plane between the surfaces, the force required to maintain the motion will be n. if the plate was 1 cm from the bottom surface (h2) and 3 cm from the top (h1) surface, the force required to maintain the motion would be n.

The image below shows numerous volcanic mountains in the pacific northwest. what is the most likely cause of the volcanic and earthquake activity in this region?

Avertical clean glass piezometer tube has an inside diameter of d = 1 mm and is used to measure pressure in a horizontal pipe carrying water as shown. due to pressure in the pipe, the water at 20c rises into the tube to a height h. if the water pressure in the pipe is p = 500 pa gauge, estimate the height h: (a) without considering surface tension (b) with surface tension (capillary) effects. the contact angle  can be assumed at 30 deg