Asprinter explodes out of the starting block with an acceleration of +4.2 m/s2, which she sustains for 0.9 s. then, her acceleration drops to zero for the rest of the race. (a) what is her velocity at t = 0.9 s. m/s (b) what is her velocity at the end of the race? m/s

Atriangle with equal sides of length 10 cm has -2.5-nc charged objects at each corner. part a determine the direction of the electrical force exerted on the object at the top corner due to the two objects at the horizontal base of the triangle. determine the direction of the electrical force exerted on the object at the top corner due to the two objects at the horizontal base of the triangle. horizontally rightward vertically downward vertically upward horizontally leftward