A 30.0-kg child sits on one end of a long uniform beam having a mass of 20.0 kg, and a 40.0-kg child sits on the other end. The

Answer:

option D.

Explanation:

The correct choice is option D.

For an object in equilibrium, the torque measured at any point will be zero.

An object is deemed to be in equilibrium when the net moment acting on it equals zero.

If the object experiences a net moment not equal to zero, it will rotate and will not remain stable.

Answer:

50 meters

Explanation:

The acceleration of an object will always align with the direction of the resultant force acting upon it. Thus, we can find horizontal acceleration by examining the horizontal force applied, applying Newton's second law in its mathematical form: Force = mass * acceleration. Therefore, acceleration = force / mass. By inputting the numbers, we have a = 100 / 0.15, which results in a = 666.7 m/s². Consequently, the acceleration experienced by the hockey puck is 670 m/s².

Answer:

             U = 1 / r²

Explanation:

In this problem, the task does not require calculating potential energy via the force equation since these two variables are interconnected.

             

         F = - dU / dr

This derivative represents a gradient, meaning it indicates direction, leading us to write

          dU = - F. dr

The formula for force becomes

         F = B / r³

Now, let’s apply this in the integral:

          ∫ dU = - ∫ B / r³  dr

Here, the force aligns with the displacement, simplifying the scalar product to the product of magnitudes.

Now, we can solve the integrals:

            U - Uo = -B (- / 2r² + 1 / 2r₀²)

To finalize the calculations, a reference point for energy must be designated; commonly, potential energy is set to zero (Uo = 0) at infinity (r = ∞).

             U = B / 2r²

Substituting B = 2, we arrive at:

             U = 1 / r²

Answer:900 feet

Explanation:

Given

Velocity

It takes 100 feet to come to a stop.

Utilizing the equation of motion

Where

v,u=Final and initial velocities

a=acceleration

s=distance traveled

When the speed is 60 mph

s=900.08 feet