Tech A says that hydraulic braking systems use proportioning valves and metering valves. Tech B says that hydraulic braking systems use pressure differential valves, or anti-lock hydraulic control units to modify hydraulic pressure. Who is correct?

A) Tech A
B) Tech B
C) Both Techs A and B
D) Neither Tech A nor B

Diamond will scratch quartz. true or false

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s

Aracecar driver has to hold on tightly when going around a banked curve. approximately what is the centripetal force on a 2220.0 kg car going around a circle with a diameter of 190.0 meters at 25.0 m/s?