Joshua programs a robotic arm to place a block in a box by following the sequence of commands in the table. A 2-column table with 4 rows. The first column labeled step has entries 1, 2, 3, 4. The second column labeled command has entries, grip block, lift block 10 centimeters, hold for 20 seconds, release block. During which step does the robotic arm do work on the block? Step 1 Step 2 Step 3 Step 4.

Amachine, modeled as a simple spring-mass system, oscillates in simple harmonic motion. its acceleration is measured to have an amplitude of 5,000 mm/s with a fre- quency of 10 hz. compute the maximum displacement the machine undergoes during this oscillation.

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

What is friction? how does it affect the motion of an object?