8. a baseball is hit upward and travels along a parabolic arc before it strikes the se
the following statements must be true?
it strikes the ground. which of
a.
the acceleration of the ball
decreases as the ball moves upward.
c. the acceleration of the ball is zero
m/s when the ball is at the highest
point in the arc.
d. the x-component of the velocity of
the ball is the same througout the
ball's flight
b.
the velocity of the ball is zero m/s
when the ball is at the highest point
in the arc.

Along wire of diameter 1 mm is submerged in an oil bath of temperature ∞ 31°c. the wire has an electrical resistance per unit length of 0.01 ω/m. if a current of 103 a flows through the wire and the convection coefficient is 500 w/m2·k, what is the steady-state temperature of the wire? from the time the current is applied, how long does it take for the wire to reach a temperature that is within 1°c of the steady-state value? the properties of the wire are 8000 kg/m3, 500 j/kg·k, and 20 w/m·k.