Which of the following is not an example of doing work?

a. holding a tray in the cafeteria line
b. picking up a box off the floor
c. raising a barbell over your head
d. pushing a box across the floor

i will give brainliest to the first person who answers if they get it right
plz

An air-standard stirling cycle operates with a maximum pressure of 600 psia and a minimum pressure of 10 psia. the maximum volume of the air is 10 times the minimum volume. the temperature during the heat rejection process is 100°f. calculate the specific heat added to and rejected by this cycle, as well as the net specific work produced by the cycle. use constant specific heats at room temperature. the properties of air at room temperature are r

Match these items. 1. coulombs __force 2. ohms __emf 3. centimeters __resistance 4. newtons __charge 5. volts __length

Will mark as brainliest how does a catapult increase the trajectory of an object? ps. answer as if u were a 5th grader