Suppose an object has a velocity of -7 m/s at t=0. What will the velocity be after 4 seconds if the acceleration of the object is +1 m/s^2?

Vf = - 3 [m/s]

Explanation:

To solve this problem we must use the following equation of kinematics.

where:

Vf = final velocity [m/s]

Vo = initial velocity = - 7 [m/s]

a = acceleration = 1 [m/s²]

t = time = 4[s]

Now replacing:

Vf = -7 + (1*4)

Vf = - 3 [m/s]

v=ir = 3x15 =45 v

because growing process had stoped after 4-5 year