The answer they are looking for is the last one. However the last two are technically correct but the third one would result in negative work.
Answer:
The work done on the Frisbee is 1.36 J.
Explanation:
Given that,
Mass of Frisbee, m = 115 g = 0.115 kg
Initial speed of Frisbee, u = 12 m/s at a point 1 m above the ground
Final speed of Frisbee , v = 10.9674 m/s when it has reached a height of 2.00 m. Let W is the work done on the Frisbee by its weight. According to work energy theorem, the work done is equal to the change in its kinetic energy. So,

So, the work done on the Frisbee is 1.36 J. Hence, this is the required solution.
No because your opinion and beliefs answers many questions
Answer:
life (N) of the specimen is 117000 cycles
Explanation:
given data
ultimate strength Su = 120 kpsi
stress amplitude σa = 70 kpsi
solution
we first calculate the endurance limit of specimen Se i.e
Se = 0.5× Su .............1
Se = 0.5 × 120
Se = 60 kpsi
and we know strength of friction f = 0.82
and we take endurance limit Se is = 60 kpsi
so here coefficient value (a) will be
a =
......................1
put here value and we get
a =
a = 161.4 kpsi
so coefficient value (b) will be
b =
b =
b = −0.0716
so here number of cycle N will be
N = 
put here value and we get
N = 
N = 117000
so life (N) of the specimen is 117000 cycles
Answer:12.28m/s
Explanation:
momentum of baseball =mass of baseball x velocity of baseball
Momentum of baseball =0.31x21
Momentum of baseball =6.51kgm/s
For a softball to have same momentum with the baseball we can say :momentum of baseball =mass of softball x velocity of softball
6.51=0.53 x velocity of softball
Velocity of softball =6.51/0.53
Velocity of softball =12.28m/s