The formula for work is:

Given the values for force and distance, we can calculate the work done.

Note that no work is done by the force of gravity or the weight of the box, since the vertical position does not change.

Work is the product of force times a distance:

We are given the work and the distance traveled, allowing us to solve for the force. The mass of the cabinet is not necessary information.

Use the data given to calculate the kinetic energy of the rocket at the two different velocities. Then find the amount of work done using the following equation: 

Kinetic energy of the rocket at the two velocities:

The change in the kinetic energy at the two velocities:

For this problem, we are looking at the net force on the bone. Since both dogs are pulling with the same force, we can say the magnitude of the force of dog 1 equals the magnitude of the force of dog 2, but in opposite directions. Mathematically, .

To find the net force on the bone, we add the individual forces together.

We can substitute our forces into the equation for net force.

The net force is zero. Each dog pulls with equal force in opposite directions, allowing the total force to cancel out.

According to Newton's second law, . If the net force is zero, then the acceleration of the bone must also be zero.

If the drop is at rest, then that means that the net forces acting upon it are equal to zero. There are two forces acting on the drop: the force due to gravity and the frictional force of the paint on the wall.

Mathematically, we can set up an equation for the net force:

The forces of friction and gravity are going to be equal and opposite, causing the drop to remain still on the wall.

If two forces act on a single object, then the net force on the object is equal to the sum of the forces acting on it.

Forces are vector quantities, however. This means that all forces have a magnitude and a direction of action. When adding forces, we must take their directions into account. Directions are broken into horizontal and vertical portions for vector addition, and can be positive or negative based on the direction along the axis.

For a net force to be zero, one force must be positive and the other must be negative along a given axis. If the forces are of equal magnitude, then they must be acting in exactly opposite directions in order to cancel each other.

Kinetic force is not a technically correct property. Kinetic energy can be used to generate force, but is not a force in itself. Forces require non-zero acceleration, meaning that they only exist when there is a changein velocity. A change in kinetic energy can indicate a change in velocity, leading to a non-zero force value.

Normal force is the force of a surface upon an object, frequently countering gravity. Friction force is the resistance between an object and a surface, and acts opposite the direction of the object's motion. Buoyant force is the upward force of a fluid on a submerged object. Drag, or air resistance, is a special form of friction force for an object moving through a fluid.

First, realize that the force that the lighter child exerts on heavier child is equal and opposite to the force the heavier child exerts on the lighter child, as per Newton's third law.

Using Newton's second law, we can re-write this equation.

The question tells us that , making  the heavier child and  the lighter child. We can use this in our equation as well.

We are looking for the ratio of  to , so we need to rearrange the equation.

First, the masses cancel out.

Then, divide both sides by .

The ratio of   to is .

The relationship between force and acceleration is .

Since the crate has a constant velocity, it has no acceleration.

If there is zero acceleration, that means there is no net force on the object, or .

Newton's second law states that . We know the mass, but we need to calculate the acceleration.

Acceleration is the change in velocity per unit time.

Since the velocity does not change from one moment to the next, then there must be no net acceleration on the object.

Returning to Newton's second law, we can see that if there is no acceleration, then there is no net force.