course Phy 201
09-23-09 at 110pm
random_assgn_3course Phy 201
What are the acceleration and final velocity of an object whose average velocity, accelerating uniformly from rest for 7.9 seconds, is 59 cm/s? How far does the object travel during the 7.9 seconds? Average acceleration = change of velocity/ time elapsed so acceleration = 59 cm/7.9sec = 7.468 cm/sec
The units would be 59 cm/s / (7.9 s) = 7.4 cm/s^2.
And the final velocity would be 59 + 7.468 = 66.468 cm/sec.
The final velocity is not obtained by adding the acceleration to the iniital velocity, but by adding the change in velocity to the initial velocity.
And the distance traveled = time * average speed so distance traveled = 7.9 * 7.468 = 58.997 cm.
7.468 is the numerical value of the acceleration and is not an average speed.
These quantities do need to be expressed in terms of their units.