A student needs to move a large carton of books with a total mass of 120 kg, to get a better view out the window. The coefficient of static friction (μs) between the cardboard boxes and the tile floor is 0.42, and the coefficient of kinetic friction (μk) is 0.30. With what horizontal force will the student have to push in order to get the stack of books to start moving? Round to the nearest whole number and include units.

During spring semester at mit, residents of the parallel buildings of the east campus dorms battle one another with large catapults that are made with surgical hose mounted on a window frame. a balloon filled with dyed water is placed in a pouch attached to the hose, which is then stretched through the width of the room. assume that the stretching of the hose obeys hooke's law with a spring constant of 89.0 n/m. if the hose is stretched by 5.80 m and then released, how much work does the force from the hose do on the balloon in the pouch by the time the hose reaches its relaxed length? unitst 3 number-1497 the tolerance is +/-5% open show work click if you would like to show work for this question:

Which statement correctly describes a step-up transformer? a. it increases the amount of electric energy available. b. it increases the voltage of an electric current. c. it changes direct current into alternating current. d. it has more loops of wire in its primary coil.

What are similarities and differences between refraction, reflection, diffraction and absorption?