Simple Work and Energy question

[pinkerpikachu]

A) the force required to give a helicopter of a mass M an acceleration of .10g upward.
B) Find the work done by this force as the helicopter moves a distance of h upward

I'm not incompetent or totally clueless about this.I know that F=ma and W=Fx

So, my solutions:

a) F=ma
F= .10Mg

b) W=Fx
W=.10Mgh


But the answer in the back of my book has a) 1.10Mg B) 1.10Mgh so either I'm missing some crucial step, or my book has a typo

help please?

 

[LowlyPion]

A) the force required to give a helicopter of a mass M an acceleration of .10g upward.
B) Find the work done by this force as the helicopter moves a distance of h upward

I'm not incompetent or totally clueless about this.I know that F=ma and W=Fx

So, my solutions:

a) F=ma
F= .10Mg

b) W=Fx
W=.10Mgh


But the answer in the back of my book has a) 1.10Mg B) 1.10Mgh so either I'm missing some crucial step, or my book has a typo

help please?

Unfortunately you forgot that the Helicopter has a weight of m*g.
To accelerate it another .1g means that it must overcome the original m*g and then add the extra .1*m*g.

 

[baba89]

I would first check to see if there is a typo in the book. If there is no typo, then I would approach the problem by breaking down the force and work into components.

First, let's define the force required to give the helicopter an acceleration of 0.10g upward as F. This force can be broken down into two components: the force of gravity (mg) and the force required to accelerate the helicopter upward (F').

F = mg + F'

Next, we can use the equation F=ma to solve for F':

F' = ma

F' = m(0.10g)

F' = 0.10mg

Now, we can plug this value back into our original equation to solve for F:

F = mg + 0.10mg

F = 1.10mg

This is the force required to give the helicopter an acceleration of 0.10g upward.

To find the work done by this force as the helicopter moves a distance of h upward, we use the equation W=Fx. However, since the force is not acting in the direction of motion, we need to use the component of the force that is acting in the direction of motion. In this case, it is the force required to accelerate the helicopter upward (F').

So, W = F'x

W = (0.10mg)h

W = 0.10mgh

This is the work done by the force as the helicopter moves a distance of h upward.

Therefore, the correct answers should be:

a) 1.10mg

b) 0.10mgh

I hope this helps clarify the problem and your understanding of work and energy. Remember to always double check for typos and break down the problem into components if needed.