During the stage of internal combustion engine operation in which the piston rises and compresses the fuel in the combustion chamber,
a. both the intake and exhaust valves are closed.
b. both the intake and exhaust valves are open.
c. the exhaust valve is open and the intake valve is closed.
d. the intake valve is open and the exhaust valve is closed.

Aparticle initially located at the origin has an acceleration of = 2.00ĵ m/s2 and an initial velocity of i = 8.00î m/s. find (a) the vector position of the particle at any time t (where t is measured in seconds), (b) the velocity of the particle at any time t, (c) the position of the particle at t = 7.00 s, and (d) the speed of the particle at t = 7.00