PHYSICS 7B Lecture 15: PHYSICS7B_10-9-15

Un automovil transita por una curva en forma de U y recorre una distancia de 400m en 30seg sin embargo su posicion final esta a solo 40m de la inicial ¿cual es la rapidez media y cual es la magnitud de la velocidad media?

At time t = 0 a 2-kg particle has a velocity of (4m/s)ˆi− (3m/s)ˆj.At t = 3 s its velocity is
(2m/s)ˆi + (3m/s)ˆj. During this time the work done on itwas:
A. 4 J
B. −4J
C. −12 J
D. −40 J
E. (4 J)ˆi + (36 J)ˆj

A particle moves in the xy plane with constant
acceleration. At time zero, the particle is at
x = 9 m, y = 2 m, and has velocity ~vo =
(9 m/s) ˆi + (-7.5 m/s) ˆ? . The acceleration is
given by ~a = (1.5 m/s
2
) ˆi + (3 m/s
2
) ˆ? .
What is the x component of velocity after
4 s?