John played a note on his tuba that vibrated the air 50 times per second. If he played the note for 2 seconds, how many times did the air vibrate?

100 times

Step-by-step explanation: vibration per second: 50 times

                               vibration for 2 seconds; 50*2=100 times

the correct answer option is d. la = πrs.

step-by-step explanation:

we know that for a right cone, the lateral surface area is given by:

lateral area of right cone =

here the value under the square root is equal to slant height so replacing this value by in the formula to get:

lateral area of right cone =

therefore, the correct answer option is d.