Jonathan is riding a bicycle and encounters a hill of height 7.30 m. at the base of the hill, he is traveling at 6.00 m/s. when he reaches the top of the hill, he is traveling at 1.00 m/s. jonathan and his bicycle together have a mass of 85.0 kg. ignore friction in the bicycle mechanism and between the bicycle tires and the road. (a) what is the total external work done on the system of jonathan and the bicycle between the time he starts up the hill and the time he reaches the top? (b) what is the change in potential energy stored in jonathan’s body during this process? (c) how much work does jonathan do on the bicycle pedals within the jonathan-bicycle-earth system during this process?

What is the conversion factor between kg/m^3 and g/m^3. express your experimental values for the densities in kg/m^3.

Dinate system, and a charge q = - 2.00 nc is placed s2 10 n> c. (a) what is the change in electric potential energy when the dipole moment of a molecule changes its orientation with respect to es from parallel to perpendicular? (b) at what absolute temperature t is the average translational kinetic energy 32 kt of a molecule equal to the change in potential energy calculated in part(: abovethistemperature,thermalagitationprevents the dipoles from aligning with the electric field.) placed in a uniform electric field e with magnitude 1.6 * 6 on the positive x-axis at x = 4.00 cm. (a) if a third charge q3 = +6.00 nc is now placed at the point x = 4.00 cm, y = 3.00 cm, find the x- and y-components of the total force exerted on this charge by the other two. (b) find the magnitude and direction of figure p21.62 ll uu 21.55 . torque on a dipole. an electric dipole with dipole moment ps is in a uniform external electric field es. (a) find the orientations of the dipole for which the torque on the dipole is zero. (b) which of the orientations in part (a) is stable, and which is unstable? (hint: consider a small rotation away from the equi- librium position and see what happens.) (c) show that for the stable orientation in part (b), the dipole’s own electric field tends to oppose the external field. 21.62 ..

Apotter's wheel moves uniformly from rest to an angular speed of 0.20 rev/s in 32.0 s. (a) find its angular acceleration in radians per second per second. rad/s2 (b) would doubling the angular acceleration during the given period have doubled final angular speed?