PLEASE HELP!

5. Salim has a paper route. In the winter time, he puts his newspapers on a toboggan to pul them through the snow. The combined mass of the papers and the toboggan is 24 kg. The coefficient of static friction between the toboggan and the snow is 0.18. The coefficient of kinetic friction between the toboggan and the snow is 0.10. (3 marks) a) With how much force must Salim pull in order to get the toboggan too start moving? b) How much force is needed to keep the toboggan moving at a constant speed?

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

Amerry-go-round of radius r, shown in the figure, is rotating at constant angular speed. the friction in its bearings is so small that it can be ignored. a sandbag of mass m is dropped onto the merry-go-round, at a position designated by r. the sandbag does not slip or roll upon contact with the merry-go-round. how would you rank the following different combinations of m and r on the basis of the angular speed of the merry-go-round after the sandbag "sticks" to the merry-go-round from largest to smallest. a) m = 10kg, r = 0.25r b) m = 20kg, r = 0.25r c) m = 10kg, r = 0.50r d) m = 10kg, r = 1.0r e) m = 15kg, r = 0.75r f) m = 40kg, r = 0.25r

The index of refraction of the oil is 1.20. what is the minimum thickness t of the oil slick at that spot?