Answer:
The hiker has to climb 941.26 to ''work off'' the calories.
Explanation:
Let's first find out how much energy the hiker gets from 150 food calories.
This is:
Energy = 150 * 4186
Energy = 627.9 kJ
To burn all of this off, we set it equal to the gravitational potential energy, and then solve for the height.
This is:
Gravitational Potential Energy (G.P.E) = 629700
G.P.E = mass * gravity * height
Thus,
mass * gravity * height = 629700
68 * 9.81 * height = 629700
height = 941.26 meters
Answer:
Like charges repel each other; unlike charges attract. Thus, two negative charges repel one another, while a positive charge attracts a negative charge. The attraction or repulsion acts along the line between the two charges. The size of the force varies inversely as the square of the distance between the two charges.
What is missing is the density of salt water. Let's denote it ρ.
<span>The pressure at depth d then is: </span>
<span>p = p0 + ρ g d </span>
<span>, where p0 is the atmospheric pressure at the surface of the sea. We assume it is equal to the 1 atm inside the sub. </span>
<span>Hence the pressure difference between inside and outside of the window is: </span>
<span>Δp = ρ g d </span>
<span>The force on the window is this pressure difference, multiplied by the area of the circular window of diameter D. The latter equals </span>
<span>A = ¼ π D². </span>
<span>So </span>
<span>F = p A = ¼ π D ²ρ g d. </span>
<span>This should be less than Fmax. </span>
<span>Hence d < Fmax / (¼ π D ²ρ g ). </span>
Velocity is a vector quantity, follows law of vector addition, has both direction and magnitude while speed is a scalar quantity , follows law of algebra and only has magnitude
Answer: -4.4 m/s
Explanation:
This problem can be solved by the Conservation of Momentum principle, which establishes that the initial momentum
must be equal to the final momentum
:
(1)
Where:
(2)
(3)
is the mass of the child
is the initial velocity of the child
is the mass of the adult
is the initial velocity of the adult (it is sitting still)
is the final velocity of the child
is the final velocity of the adult
Substituting (2) and (3) in (1):
(4)
Isolating
:
(5)
(6)
Finally:
This means the velocity of the child is in the opposite direction