Question

What formula do I use for the second question? For number 3 how is one energy converted to the other? ( using arrows ) I get number 4 so I don't need help with that!

Answer 1

#2
Use the formula ... Kinetic energy = (1/2) x (mass) x (speed)²

#3 - a).
sun => energy travels as electromagnetic waves => reaches Earth as
         heat & light energy.

sun => absorbed in plants => eaten by animals => animals die =>
       decay into oil in millions of years => we burn the oil to get the energy.

#3 - b).
food I ate for lunch => metabolized into glucose by my body
       => some of it burned in my muscles to generate energy for immediate needs
       => the rest of it stored as fat for future needs.

#3 - c).
flower pot rolls off the ledge => gravity does work on it all the way down,
       producing the kinetic energy it has when it hits the floor.

#3 - d).
oil or natural gas is burned, releasing heat energy => energy is used
       to generate electricity => electricity flows through cables from the
       power generating plant to your home => hot plate plugged into the
       wall => turns electrical energy back into heat energy => heat energy
       is conducted into the bottom of the beaker, flows through the glass
       to the inside surface => heat energy is conducted from the inside of
       the glass to the water, which gets hotter as it absorbs more energy. 
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Note:
#1 on the sheet is wrong.
"Work = force x distance"  that's correct
But 25-kg is the mass of the ball, not the gravitational force on it.
The force on it is (mass) x (gravity), called its "weight".
   That's (25-kg) x (9.8 m/s²) = 245 kg-m/s² = 245 newtons .