Type the correct answer in each box. Round your answers to the nearest hundredth.

A ball with a mass of 1.5 kilograms is tied to the end of a rope. The ball is pulled to a height of 0.5 meters above the ground and released.

The ball has [tex]\square[/tex] joules of potential energy at position B. At position A, all of the energy changes to kinetic energy. The velocity of the ball at position A is [tex]\square[/tex] meters/second. Assume there's no air resistance. Use [tex]g = 9.8 \, m/s^2[/tex], [tex]PE = m \times g \times h[/tex], and [tex]v = \sqrt{\frac{2KE}{m}}[/tex].



Answer :

Let's break down the problem step-by-step.

1. Calculate the potential energy (PE) at position B:

The formula for potential energy is given by:

[tex]\[ PE = m \times g \times h \][/tex]

where:
- [tex]\( m \)[/tex] is the mass of the ball, which is 1.5 kilograms.
- [tex]\( g \)[/tex] is the acceleration due to gravity, which is [tex]\( 9.8 \, m/s^2 \)[/tex].
- [tex]\( h \)[/tex] is the height above the ground, which is 0.5 meters.

Substituting the values into the equation:

[tex]\[ PE = 1.5 \, \text{kg} \times 9.8 \, m/s^2 \times 0.5 \, \text{m} = 7.35 \, \text{joules} \][/tex]

So, the potential energy at position B is [tex]\( 7.35 \)[/tex] joules.

2. Calculate the kinetic energy (KE) at position A:

At position A, all of the potential energy has been converted into kinetic energy, so:

[tex]\[ KE = PE = 7.35 \, \text{joules} \][/tex]

3. Calculate the velocity of the ball at position A:

The formula for kinetic energy in terms of velocity is:

[tex]\[ KE = \frac{1}{2} \times m \times v^2 \][/tex]

Rearranging to solve for [tex]\( v \)[/tex]:

[tex]\[ v = \sqrt{\frac{2 \times KE}{m}} \][/tex]

Substituting the values we have:

[tex]\[ v = \sqrt{\frac{2 \times 7.35 \, \text{joules}}{1.5 \, \text{kg}}} = \sqrt{\frac{14.7}{1.5}} = \sqrt{9.8} \approx 3.13 \, m/s \][/tex]

So, the answers are:

- The ball has [tex]\( 7.35 \)[/tex] joules of potential energy at position B.
- The velocity of the ball at position A is [tex]\( 3.13 \)[/tex] meters per second.