At a certain moment, a car travelling at 40mph begins braking for a railroad crossing. assume thatthe acceleration is constant (and negative! ) and that 2 minutes later, the car comes to a stop, justbefore the crossing.(a) find a formula for the velocity v(t) at any moment during the deceleration.(b) determine how far away from the railroad crossing the car was when it began decelerating.

Ain is , is 's of ? 0.62 0.79 1.27 1.50

Two 2.0-cm-diameter disks face each other, 1.0 mm apart. they are charged to ±10 nc. what is the electric field strength between the disks? a proton is shot from the negative disk toward the positive disk. what launch speed must the proton have to just barely reach the positive disk?

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.