Answer:
Average force is F = mass times change in V/ change in time so..
1 366.07143 N
Explanation:
51 kg x 15 m/s / 0.56
1 366.07143 m kg / s
1 366.07143 N
1 kilogram 1 meter per second per second = 1 N
Answer:
The speed of water must be expelled at 6.06 m/s
Explanation:
Neglecting any drag effects of the surrounding water we can assume the linear momentum in this case is conserves, that is, the total initial momentum of the octopus and the water kept in it cavity should be equal to the total final linear momentum. That's known as conservation of momentum, mathematically expressed as:

with Pi the total initial momentum and Pf the final total momentum. The total momentum is the sum of the momentums of the individual objects, in our case the octopus and the mass of water that will be expelled:

with Po the momentum of the octopus and Pw the momentum of expelled water. Linear momentum is defined as mass times velocity:

Note that initially the octopus has the water in its cavity and both are at rest before it sees the predator so
:

We should find the final velocity of water if the final velocity of the octopus is 2.70 m/s, solving for
:


The minus sign indicates the velocity of the water is opposite the velocity of the octopus.
Answer:
The answer is 2,416 m/s. Let's jump in.
Explanation:
We do work with the amount of energy we can transfer to objects. According to energy theory:
W = ΔE
Also as we know W = F.x
We choose our reference point as a horizontal line at the block's rest point.<u> At the rest, block doesn't have kinetic energy</u> and <u>since it is on the reference point(as we decided) it also has no potential energy.</u>
Under the force block gains;
W = F.x → 
In the second position block has both kinetic and potential energy. Following the law of conservation of energy;
W = ΔE = Kinetic energy + Potantial Energy
W = ΔE = 
Here we can find h in the triangle i draw in the picture using sine theorem;
In a triangle 
In our situation
→ 
Therefore

→ 
Answer:
1.9841256 kg
Explanation:
Given;
Length of the swimming pool = 25.0 ft = 7.62 m ( 1 ft = 0.3048 m )
Width of the swimming pool = 18.5 ft = 5.64 m
Depth of the pool = 9.0 ft =
Total depth of the water in the pool when filled = 9 ft - 7 inches = 2.56 m
now,
Volume of the water in the pool = Length × Width × Depth
or
Volume of the water in the pool = 7.62 × 5.64 × 2.56 = 110.2292 m³
also,
1 m³ = 1000 L
thus,
110.2292 m³ = 110229.2 L
also it is given that 18 mg of Cl is added to 1 liter of water
therefore,
In 110229.2 L of water Cl added will be = 110229.2 × 18 = 1984125.6 mg
or
= 1.9841256 kg