In a closed system, a cart with a mass of 1.5 kg is rolling to the right at 1.4 m/s, while another cart of mass 1.0 kg is rolling to the left at the same speed. what is the total momentum of the system of two carts?

a. 0.0 kgm/s

b. 0.50 kgm/s

c. 0.70 kgm/s

d. 3.5 kgm/s

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?

A15.75-g piece of iron absorbs 1086.75 joules of heat energy, and its temperature changes from 25°c to 175°c. what is the specific heat capacity of iron?

You can estimate the degree to which a bond between two atoms is ionic or covalent by calculating the