Agrandfather clock is controlled by a swinging brass pendulum that is 1.3m long at a temperature of 20°c.
(a) what is the length of the pendulum rod when the temperature drops to 0.0°c?
(b) if the pendulum’s period is given by t = √ / , where l is the length, does the change in length of the rod cause the clock to run fast of slow?

What is the electric force acting between two charges of -0.0045 c and -0.0025 c that are 0.0060 m apart? use fe=kq1q2/r^2 and k = 9.00 x 10^9 n*m^2/c^2 a. 1.7 x 10^7 n b. -1.7 x 10^7 n c. -2.8 x 10^9 n d. 2.8 x 10^9 n

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)

Which of the choices are parts of an atom? select all that apply. a.) compound b.) electron c.) neutron d.) molecule e.) photon f.) proton g.) element