A mass m = 0.7 kg is released from rest at the origin 0. The mass falls under the influence of gravity. When the mass reaches point A, it is a distance x below the origin 0; when the mass reaches point B it is a distance of 3 x below the origin 0. What is vB/vA?

Explanation:

Consider the two kinematic equations for velocity and position of an object falling due to the action of gravity:

Therefore, if we consider the time for the object to reach point A, and the time for it to reach point B, then:

Let's work in a similar way with the two different positions at those different times, and for which we have some information;

Notice that this quotient is exactly the square of the quotient of velocities we are looking for, therefore:

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.

that tool is called an altimeter which measures your altitude which can be used to tell which atmosphere you are currently in, including the stratosphere.

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