Two blocks are accelerated across a horizontal frictionless surface as shown. Frictional forces keep the two blocks from sliding relative to each other, and the
two move with the same acceleration. If F = 1.2 N and M-1.0 kg, what is the horizontal component (frictional force ) of the force of the small block on the large block?

0.48 N to the right
b. 0.72 N to the right
c. 0.72 N to the left
d. 0.48 N to the left
e. 0.65 N to the left

You have been hired to design a spring-launched roller coaster thatwill carry two passengers per car. the car goes up a 10-m highhill, then descends 15m to the track's lowest point. you'vedetermined that the spring can be compressed a maximum o 2.0m andthat a loaded car will have a maximum mass of 400kg. for safetyreasons, the spring constant should be 10% larger than the minimumneeded for the car to just make it over the top. a) what spring constant (k) should you specify ? b) what is the maximum speed of a 350 kg car if the spring iscompressed the full amount.