One particle has a charge of 4.2 x 10-9 C, while another particle has a charge of 1.10 x 10-9 C. If the two particles are separated by 0.005 m, what is the
electromagnetic force between them? The equation for Coulomb's law is
Fe = k992, and the constant, k, equals 9.00 x 109 Nm2/C2.
A. 8.31 x 10-6N
B. 1.66 x 10-5 N
C. 1.85 10-13 N
D. 1.66 10-3 N

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.

What type of force holds atoms together in a crystal?

When a pendulum is held high and taut and then is released, the pendulum begins to swing. what’s the correct order of the energy transformations in this example? (pe stands for potential energy.)