There are tons of forces that balance out on your body while you walk. Subsequent physics classes will tell you about each and how they are represented. Here are a few in order of how people usually learn them.
Gravity: The earth exerts a gravitational force on each particle in your body that has mass. Overall, this can be represented as a single force that pulls directly toward the center of the earth from the point called your center of mass.
Normal Force: The contact between your feet/shoes and the ground exerts a force normal (straight out from) the ground. If you are on flat ground, this force is directly opposite the force of gravity, and in most cases will be equal to it such that you have no vertical net force.
Friction: Friction between your shoes/feet and the ground, pointing parallel to the ground and in the direction of your walking motion creates the force necessary for you to move. The microscopic peaks and valleys of the ground and your feet/shoes create small normal forces that can sum into a direction of motion.
Air Buoyancy: Since you are in a fluid, the mass of the fluid you displace creates an upward force away from the center of the earth. Since the density of air is miniscule, this force is generally neglected except in the most precise of circumstances.
Drag and Air resistance: While you walk, as you move through a fluid, that fluid exerts friction on your body in the form of drag. It is usually small unless you’re moving very fast relative to the fluid.
Air pressure, blood pressure, body tensions: Your body has a balance of blood pressure, muscle tensions, which oppose outside air pressures which equalize out to form the shape your body is in.
Internal forces: Many forces act within you such as air pressure, other muscle tensions, and internal stresses which balance out. Usually in physics these are lumped under internal forces.
Answer:
Explanation:
Here we know that initial temperature of ice is given as
now the latent heat of ice is given as
now we also know that the mass of ice is
so here we know that heat required to change the phase of the ice is given as
The mass is missing. The mass of the elevator is 1650 kg.
Answer:
The tension in the cable is 19387.5 N.
Explanation:
Given:
Initial velocity of the elevator (u) = 0 m/s
Acceleration in the upward direction (a) = 1.95 m/s²
Time taken by the elevator (t) = 2.15 s
Mass of the elevator and persons (m) = 1650 kg
Let the tension in the cable wire be 'T' Newtons.
Now, there are 2 forces acting in the vertical direction. One is tension in the upward direction and the other the weight of the elevator in the downward direction.
As the elevator is accelerating upward, the net force acts in the upward direction.
So, net force on the elevator is given as:
Now, from Newton's second law, net force equals mass times acceleration.
Plug in the given values and solve for 'T'. This gives,
Therefore, the tension in the cable is 19387.5 N.
Answer:
X = 2146.05 m
Explanation:
We need to understand first what is the value we need to calculate here. In this case, we want to know how far from the starting point the package should be released. This is the distance.
We also know that the plane is flying a certain height with an specific speed. And the distance we need to calculate is the distance in X with the following expression:
X = Vt (1)
However we do not know the time that this distance is covered. This time can be determined because we know the height of the plain. This time is referred to the time of flight. And the time of flight can be calculated with the following expression:
t = √2h/g (2)
Where g is gravity acceleration which is 9.8 m/s². Replacing the data into the expression we have:
t = √(2*2500)/9.8
t = 22.59 s
Now replacing into (1) we have:
X = 95 * 22.59
<h2>
X = 2146.05 m</h2>
This is the distance where the package should be released.
Hope this helps
