You are trying to lift a stack of books off the table. The stack of books has a mass of 15 kg. What minimum upward force must you exert on the books if you want to lift the books off the table? Remember to take your answer to 2 decimal places.

A passenger is standing on a scale in an elevator. The building has a height of 500 feet, the passenger has a mass of 80 kg, and the scale has a mass of 7 kg. The scale sits on the floor of the elevator. (It is an Otis elevator, so we will label it as "O" so as not to confuse its forces with those caused by the earth.) You may take g = 10 N/kg. For doing this problem it might be useful to start by drawing free-body diagrams for the passenger and the scale. Consider the vertical forces acting on the passenger and the scale WE→P: The force of the earth pulling down on the passenger (weight). WE→S: The force of the earth pulling down on the scale (weight). NP→S: The force of the passenger pushing down on the scale (normal). NS→P: The force of the scale pushing up on the passenger (normal). NO→S: The force of the elevator pushing up on the scale (normal). NO→P: The force of the elevator pushing up on the passenger (normal). Which of these forces affect the motion of the passenger? Select…

The figure shows a section of a cable-car system. The maximum permissible mass of each car with occupants is 2200 kg. The cars, riding on a support cable, are pulled by a second cable attached to the support tower on each car. Assume that the cables are taut and inclined at angle 0 = 39º. What is the difference in tension between adjacent sections of pull cable if the cars are at the maximum permissible mass and are being accelerated up the incline at 0.85 m/s²? Number Units Support cable- Pull cable

You are a bully.  You pin a 48 kg dweeb to a wall so that his feet aren't touching the ground.  Your arm is extended so that it makes an angle 28 degrees with the horizontal.  The dweeb's back is so sweaty with fear that there is no friction between his back and the wall.  What is the magnitude of the force , in N, you must apply to keep the dweeb in equilibrium? (Use g = 10 m/s2) This scenario is represented schematically below.  Unfortunately for you, years later the dweeb is your boss and he makes your life miserable. (Please answer to the fourth decimal place - i.e 12.3445)

Due to a jaw injury, a patient must wear a strap that produces a net upward force of 5.00 N on his chin. The tension is the same throughout the strap. To what tension must the strap be adjusted to provide the necessary upward force?

You have devised an experiment to measure the kinetic coefficient of friction between a ramp and a mass. You place the mass on the ramp at an angle high enough that the mass starts sliding. You measure the time it takes to fall down a known distance. The time it takes to fall down the 45 degree ramp starting from a standstill is At = 0.46 sec, m=1 kg, and the distance it falls, Ax , is 0.5 m. What is µk? m Дх in At Uk

. A 25kg wooden plate is held in place by two strings attached to the ceiling and the wall. The string attached to the ceiling makes an angle 40° with the horizontal and the string attached to the wall makes 90° with the wall. Determine the force in each string.

Suppose you have a stack of 17 identical steel bars (steel bars have a mass of 1.00kg each). You are required to pull out bar number 16 from the stack (counting from the top of the stack down). Assuming that your assistant holds all other bars in place.   If the coefficient of friction between steel and steel is 0.750, how hard do you have to pull (in N)?

(a) A 4.53 kg salami is supported by a cord that runs to a spring scale, which is supported by another cord from the ceiling (see Figure (a)). What is the reading on the scale, which is marked in weight units? (b) In Figure (b) the salami is supported by a cord that runs around a pulley and to a scale. The opposite end of the scale is attached by a cord to a wall. What is the reading on the scale? (c) In Figure (c) the wall has been replaced with a second 4.53 kg salami on the left, and the assembly is stationary. What is the reading on the scale now? Spring scale Spring scale (6) Spring scale (a) (c) (a) Number i Units (b) Number i Units (c) Number i Units

A wracking ball is suspended below two cables each at an angle with the horizontal. The left cable has tension T1 and angle 39 degrees with the horizontal. The right cable has tension T2 and angle 24 degrees with the horizontal. The Wracking ball has mass 160 kg.