Question

The initial speed of a body is 2.98 m/s.What is its speed after 1.6 s if it accelerates uniformly at 2.51 m/s^2?
Answer in units of m/s


What is its speed after 1.6 s if it accelerates uniformly at −2.51 m/s^2?
Answer in units of m/s

Answer 1

V (ending) = at + v (initial)

V= (-2.51) (1.6) + 2.98

V= -1.036 m/s

V (using significant figures) = -1.0 m/s

Answer 2

Not sure if you are saying the acceleration is positive or negative?
The equation you would use would be v=u+at, where v=final velocity u=initial velocity a=acceleration t=time. Using this if the acceleration is 2.51m/s^2:
v=2.98+(2.51*1.6)
v=6.996m/s
If the acceleration is -2.51 m/s^2:
v=2.98+(2.51*1.6)
v=-1.036m/s