Hi! Would one of you please check my work? Thanks! ( I used significant digits, by the way)
A student throws a 5.00 kg steel shot directly upwards so that it leaves his hand when it is 2.00 m above the ground. If its velocity is 0.15 m/s when it leaves his hand, calculate:
1.The shot's potential energy in the student's hand before he throws it
* I got 98.1 J
2.The work done to accelerate it to 15.0 m/s
* I got 98.1 J
3. The kinetic energy when it leaves his hand
* I got 5.6 * 10^-2 J
4. The total mechanical energy of the shot
* I got 98.2 J
5. The height above his hand where it stops rising
* I got 0.00115 m
6. The height above the ground at that point
* I got 2.00115 m
7. The potential energy relative to the ground at that point
* I got 98.16 J
8. The kinetic energy just before it strikes the ground
*I got 98.16
9. The velocity with which it strikes the ground
* I got 6.3 m/s
you seem to have both 15 and .15 for the velocity. Compromise at 1.5 maybe?
Hmmm... The worksheets lists both 0.15 and 15 as velocity (?)Perhaps they forgot to put the decimal.
Will I not get a different answer if the velocity is different, like you suggested?
Thanks!
1. Correct
3. Correct
5. Correct
6. Correct.
7. Correct
8. Correct
9. Correct.
Thanks you Henry! I still would like to know if 2 and 4 are correct, thank you!
2 and 4 are correct as are others using 0.15 for initial velocity up. However I am quite sure that was not the intent because the velocity is so low it makes little sense and the shot hardly gets above the hand.
Thanks! I will have to ask my teacher about the low velocity bit..
Yes, I noticed that the initial velocity
was unusually low; but I assumed that a
change in velocity would change the
answer but not the procedure.