Question

If the velocity of an object changes from 15 m/s to 50 m/s during a time interval of 4 s, what is the acceleration of the object? If the acceleration in problem 4 is constant, what's the average velocity of the object in the previous problem?

Answer 1

The object's average acceleration over the 4s interval would be

`a_(\rm avg)=(50\,(\rm m)/(\rm s)-15\,(\rm m)/(\rm s))/(4\,\rm s)=8.75\,(\rm m)/(\rm s)`

Under constant acceleration, the average veclocity of an object with initial velocity
`v_i` and final velocity
`v_f` is

`v_(\rm avg)=\frac{v_f+v_i}2`

so assuming "problem 4" refers to the first question, the average veclocity of the object would be

`v_(\rm avg)=\frac{50\,(\rm m)/(\rm s)+15\,(\rm m)/(\rm s)}2=16.25\,(\rm m)/(\rm s)`