18 bags of sand will be needed
It is 70% Because:
250/100 + 175/x
Proportions
Answer:
4.1 N
Step-by-step explanation:
We can solve this problem by using considerations about energy.
At the moment the stone is dropped, it has only gravitational potential energy:

where
is the weight of the stone
h = 10 m is the initial height of the stone
As the stone falls, part of this energy is converted into kinetic energy, while part into thermal energy due to the presence of the air friction, acting opposite to the motion of the stone:

where:
is the mass
v = 13 m/s is the final speed of the stone
is the thermal energy
The thermal energy is actually equal to the work done by the air friction on the stone:

where
F is the average force of friction
h = 10 m
Since the total energy must be conserved, we can combine the three equations, so we find:

And solving for F, we find the average force of air friction:







Note
Write the number until underlined point.I did it till end
Answer:
x = 3/2
The axis of symmetry is located at the vertex,
which is the also the highest point in this problem...
the x component of the vertex can be calculated as -b/2a = -48/-32 = 24/16 = 6/4 = 3/2
x = 3/2
Step-by-step explanation: