A dock worker applies a constant horizontal force of 81.0 N to a block of ice on a smooth horizontal floor. The frictional force is negligible. The block starts from rest and moves a distance 13.0 m in a time of 5.20 s . Required:
a. What is the mass of the block of ice?
b. If the worker stops pushing at the end of 5.00 s, how far does the block move in the next 5.00 s?

The correct answer is:

(a) 84.240 kg

(b) 24.038 m

Explanation:

The given values are:

Force,

F = 81.0 N

Distance,

S = 13.0 m

Time,

t = 5.20 s

As we know,

The acceleration of mass will be:

⇒  

On substituting the given values, we get

⇒    

⇒    

⇒    

(a)

The mass of the block will be:

⇒  

On substituting the given values, we get

⇒      

⇒      

(b)

The final velocity after a given time i.e.,

t = 5.00 s

⇒  

On substituting the values, we get

⇒    

⇒    

In time, t = 5.00 s

The distance moved by the block will be:

⇒  

On putting the values, we get

⇒    

⇒    

! 55 !  

write a paragraph or story to explain the transformation between potential and kinetic energy as shown in your picture or model.  

you should have at least 5 complete sentences with a main idea and supporting details.  

you must include the following words:  

potential energy

kinetic energy

mechanical energy

conservation of energy

dude, this is hard lol : ))