Calvin and Hobbes decide to go sledding, and Calvin is determined to go off a jump. Hobbes is worried they will fly through the air and crash and burn (which Calvin believes is half the fun). Let’s find out if Hobbes has anything to worry about. Their sled reaches the bottom of the jump (shown below) with a speed of 9 m/s.
The coefficient of friction between their sled and the snow is 0.18.

Draw a FBD for Calvin and Hobbes for when they are moving up the slope of the jump.

Find their net acceleration.

If the length of the jump is 7.5m, will they fly through the air? If not, how far up the slope do they make it?

EXTRA CREDIT

Calvin was not satisfied with the results of the last attempt, so he polishes the bottom of their sled with some wax to decrease the coefficient of friction by a factor of 2, causing them to reach the bottom of the jump with a speed of 11 m/s. How far will they fly through the air before landing (assume a horizontal surface even with the top of the jump)?

You are still fascinated by the process of inkjet printing, as described in the opening storyline for this chapter. you convince your father to take you to his manufacturing facility to see the machines that print expiration dates on eggs. you strike up a conversation with the technician operating the machine. he tells you that the ink drops are created using a piezoelectric crystal, acoustic waves, and the plateau-rayleigh instability, which creates uniform drops of mass m = 1.25 ✕ 10−8 g. while you don't understand the fancy words, you do recognize mass! the technician also tells you that the drops are charged to a controllable value of q and then projected vertically downward between parallel deflecting plates at a constant terminal speed of 20.0 m/s. the plates are ℓ = 2.15 cm long and have a uniform electric field of magnitude e = 6.40 ✕ 104 n/c between them. noting your interest in the process, the technician asks you, "if the position on the egg at which the drop is to be deposited requires that its deflection at the bottom end of the plates be 0.17 mm, what is the required charge on the drop (in c)? " you quickly get to work to find the answer. (neglect the force of gravity.)