Question

I need this type out answer question.

Answer 1

Answer:

The ball has 7.35 joules of energy at position B.

The velocity of the ball at position A is 3.13 meter/second

Explanation:

Kinetic and Gravitational Potential Energy

Kinetic energy is the form of energy that an object or a particle has by reason of its motion. An object of mass m and speed v has kinetic energy calculated by:

$\displaystyle K=\frac{1}{2}m.v^2$

Gravitational Potential Energy is the form of energy that an object has by reason of its height h relative to a certain reference. It can be calculated as follows:

$U=m.g.h$

Where g is the acceleration of gravity.

The figure shows a pendulum with a bob (ball) of mass m=1.5 Kg. When it's pulled to point B, it has a height of h= 0.5 m and set to rest.

The potential energy at that point is:

$U=1.5\ Kg\cdot 9.8 \ m/s^2\cdot 0.5\ m$

$U=7.35\ J$

The ball has 7.35 joules of energy at position B.

When the ball is released, all of the potential energy is transformed into kinetic energy when reaches point A. Thus:

K=7.35 J

From the equation of kinetic energy, we solve for v:

$\displaystyle v=\sqrt{\frac{2K}{m}}$

$\displaystyle v=\sqrt{\frac{2\cdot 7.35}{1.5}}$

$\displaystyle v=\sqrt{\frac{14.7}{1.5}}$

$\displaystyle v=\sqrt{9.8}$

v = 3.13 m/s

The velocity of the ball at position A is 3.13 meter/second