Question

Early one February morning you go outside to build a snow man. You make a 3.2kg snowball and lift it to a height of 1.2m, then carry it 25m on level ground with a force of 1.0N to your snowman and then lift it up the rest of the way to set as the head of a 2.3m snowman. How much work do you do on the snowball as you transport it and position it on your masterpiece?

Answer 1

First the amount of work done in lifting up the snow ball to a height of 1.2m is equal to the potential energy of the ball after the lift.

Therefore mass× gravitational pull×height will give us the work done

=3.2kg ×9.8N/kg×1.2m

=37.632J

then, the work done over the 25m distance if found by the following formula: work done=force×distance

=1.0N×25m

=25J

On reaching the headless snowman you have to lift the ball a further 1.1m to place it as the head 2.3m high.

therefore this will be a change in potential energy which is equal to work done in lifting the ball the additional 1.1m

=m×g×h

=3.2kg×9.8N/kg×1.1m

=34.496J

To get the total we add the amount of work done in the various instances.

Answer 2

Here you go

First the amount of work done in lifting up the snow ball to a height of 1.2m is equal to the potential energy of the ball after the lift.

Therefore mass× gravitational pull×height will give us the work done

=3.2kg ×9.8N/kg×1.2m

=37.632J

then, the work done over the 25m distance if found by the following formula: work done=force×distance

=1.0N×25m

=25J

On reaching the headless snowman you have to lift the ball a further 1.1m to place it as the head 2.3m high.

therefore this will be a change in potential energy which is equal to work done in lifting the ball the additional 1.1m

=m×g×h

=3.2kg×9.8N/kg×1.1m

=34.496J

To get the total we add the amount of work done in the various instances.