What are the solutions to these work and energy problems?

[losthelp]

Work and energy problems :(

can anyone help me w. these, I am completely lost!

A 0.046-kg ball is dropped froma height of 6m above the ground. When it is 1m above the ground, its velocity will be:

An object is dropped from a small height h above the ground. When its height is 0.5h, its velocity will be:

A football player cfan expend 100J energy on the football when he throws it. If the average distance through which eh accelerates is 1.2m what is the average force that he exerts on the ball?

i know these are suppose to be simple but I am compeltey lost :( help please!

 

[Sakha]

First you need formulas, all this problems are straightforward, so just get the formulas and plug in values.

 

[baba89]

There are a few different approaches to solving these work and energy problems, but the most common method is to use the equations for work and energy.

For the first problem, you can use the equation for gravitational potential energy (PE = mgh) to find the initial potential energy of the ball at a height of 6m. Then, you can use the equation for kinetic energy (KE = 1/2mv^2) to find the kinetic energy of the ball when it is 1m above the ground. Finally, you can use the conservation of energy principle (PE + KE = constant) to find the velocity of the ball at that point.

For the second problem, you can use the same approach as above, but you will need to use the initial height (h) and final height (0.5h) in the equation for potential energy.

For the third problem, you can use the equation for work (W = Fd) to find the work done by the football player on the ball. Then, you can use the equation for kinetic energy (KE = 1/2mv^2) to find the kinetic energy of the ball after it has been thrown. Finally, you can use the conservation of energy principle (KE = W) to find the average force exerted by the player on the ball.

It is important to remember to use consistent units (e.g. meters, kilograms, joules) throughout your calculations. It may also be helpful to draw a diagram or visualize the situation to better understand the problem and determine which equations to use. I hope this helps you in solving these problems.