This is a trick question. THe amount of gravitational potential energy stored at the top has to equal the final KEnergy.
GPE = mgh= 3kg*9.8*1= 29.4J
Now, for folks who are gluttons for punishment, we can do it that way.
what is the velocity from falling?
Vf^2=Vi^2+2gd= 2*9.8*1= 19.6
Vf= sqrt (19.6)
KE= 1/2 m v^2= 1/2 *3*19.6= 3/2 19.6=29.4J
A 3.00 kg toy falls froma height of 1.00m. What will the kinetic energy of the toy be just before it hits the ground. No air resistance and g=9.81m/s
Amswers: 0.98J
9.8 J
29.4 J
294 J
I used the formula 1/2 m times v^2
3. times 9.8^2/2 =144. Please help-what am I doing wrong?
1 answer
1 answer