A car pulls on to an onramp with an initial speed of 23.8 mph. The length of the onramp is 852 ft and the car needs to be moving at 45.7 mph at the end of the ramp to merge with traffic. What constant rate of acceleration (in ft/sec2) is required in order to accomplish this

The constant rate of acceleration required in order to accomplish this is 1.921 feet per square second.

Explanation:

Let suppose that car accelerates uniformly in a rectilinear motion. Given that initial and final speeds and travelled distances are known, then the acceleration needed by the vehicle (), measured in feet per square second, is determined by the following kinematic formula:

(1)

Where:

, - Initial and final speeds, measured in feet per second.

- Travelled distance, measured in feet.

If we know that , and , then acceleration needed to accomplish the task is:

The constant rate of acceleration required in order to accomplish this is 1.921 feet per square second.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west