A body with initial velocity 8.0 m/s moves along a straight line with constant acceleration and travels 640 m in 40 s. For the 40 s interval, find (a) the average velocity, (b) the final velocity, and (c) the
acceleration.

(a) The average velocity is 16 m/s

(b) The acceleration is 0.4 m/s^2

(c) The final velocity is 24 m/s

Explanation:

Constant Acceleration Motion

It's a type of motion in which the velocity (or the speed) of an object changes by an equal amount in every equal period of time.

Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, final speed is calculated as follows:

The distance traveled by the object is given by:

(a) The average velocity is defined as the total distance traveled divided by the time taken to travel that distance.

We know the distance is x=640 m and the time taken t= 40 s, thus:

The average velocity is 16 m/s

Using the equation [1] we can solve for a:

(c) From [2] we can solve for a:

Since vo=8 m/s, x=640 m, t=40 s:

The acceleration is 0.4 m/s^2

(b) The final velocity is calculated by [1]:

The final velocity is 24 m/s

c) up is the direction the magnetic force is acting on the charge.

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.