The choices are confusing. Air, oil, and alcohol are fluids at any reasonable temperature. Dry cement is not.
Answer:
(a) 41.75m/s
(b) 4.26s
Explanation:
Let:
Distance, D = 89m
Gravity,
= 9.8 m/
Initial Velocity,
= 0m/s
Final Velocity,
= ?
Time Taken,
= ?
With the distance formula, which is
D =
+ 
and by substituting what we already know, we have:
89 =
×9.8×
With the equation above, we can solve for
:

Now that we have solved
, we can use the following velocity formula to solve for
:
, where
is also equals to
, so we have

By substituting
,
, and
,
We have:

Answer:
Explanation:
The momentum of the first piece = m v =- m x 31 i kg m/s in - x direction direction
The momentum of the second piece = -m x 31 j kg m /s in Y - direction
Total momentum = - 31 m( i + j )
To conserve momentum , the third piece must have momentum equal to this
and opposite to it
So momentum of the third piece = 3m x V = 31 m ( i +j )
V = 31/3 ( i + j ) =
Magnitude of velocity V = √2 x 31/ 3 = 14.6 m / s
Its direction will be towards the vector i + j ie 45° from x - axis in positive direction