What is the energy of a photon of light having a wavelength of 4.5 x 10-7 meters? (planck’s constant is 6.626 x 10-34 joule seconds; the speed of light is 2.998 x 108 m/s)

2.9817 x 10-40 joules

4.4143 x 10-19 joules

6.6745 x 10-26 joules second

9.9456 x 10-49 joules

19.864 x 10-26 joules/second

What tightening torque should be used for a hexagonal head screw (not split-bolt) on a 250 kcmil conductor?

An object moves from position +34m to the position -15m in 15 seconds. what is the total displacement? what is the total velocity?

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 2 options: the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the cold balloon expands and rises. the warm balloon shrinks and sinks. the warm balloon expands and rises. the cold balloon shrinks and sinks.