Force of friction

A 15kg box sits on a table. It is not moving. Please answer the following questions and show your work if possible. The force of gravity is equal to __Newtons. The force of the table against the box is the ___force. The force of the box against the table is equal to ___Newtons.

Friction

You push on a 25kg box with a force of 400 Newtons. There is 250 Newtons of friction. Please answer the following questions and show your work if possible. What is the net force in the x direction? What is the acceleration of the box? If friction were 200 Newtons, what action force would need to be applied to have constant velocity?

friction

A 25kg box sits on a ramp that is slanted 30 degress. It is not moving. Please answer the following questions and show the formula and work if possible. What is the x component of the weight along the ramp? What is the y component of the weight perpendicular to the ramp?

Body water question

Assume that the human body is 75% water. How many moles of water are in your body? How many molecules? If I am 75% water, then why am I always getting thirsty? My body weight is 165lbs.

Ultraviolet light problem

Certain crystals fluoresce when exposed to a short burst of ultraviolet light. The amount of light emitted by the crystals is both time and temperature dependent. The emitted light is maximum at the time of excitation, the output then decaying with time. Such materials can be used to measure temperature. Given are some relative fluorescent light outputs as a function of time for 4 different temperatures. You are to, first of all, in a proper fashion, graph this data (relative output vs. time) for each temperature seperately. What kind of relationship exists between the emitted light and time? Find the time constant for each temperature. Then, make a graph of the time constant as a function o... click for more