Author Question: If the displacement of an object is given in SI units by Dx = -5t + t 2, at t = 2 s its velocity and ... (Read 25 times)

shofmannx20 · **on:** Jul 28, 2018

If the displacement of an object is given in SI units by Dx = -5t + t 2, at t = 2 s its velocity and acceleration are, respectively: (Hint: Use dimensional analysis along with the equations for motion with constant acceleration.)
a. positive, positive.
c. negative, negative.
b. positive, negative.
d. negative, positive.

Question 2

A Cessna aircraft has a liftoff speed of 120 km/hr. What minimum constant acceleration does this require if the aircraft is to be airborne after a takeoff run of 200 m?
a. 2.31 m/s2
c. 4.63 m/s2
b. 2.78 m/s2
d. 5.55 m/s2