Two slits in an opaque barrier each have a width of 0.020 mm and are separated by 0.050 mm. When coherent monochromatic light passes through the slits the number of interference maxima within the central diffraction maximum: Group of answer choices is 1 is 4 is 2 is 5 cannot be determined unless the wavelength is given

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

Which of the following harmful chemicals are found in tobacco smoke? a. carbon monoxide b. carbon dioxide c. nicotine b. carbon dioxide d. both a and c

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.