Question

During a certain time interval, a 20-N object free-falls 10 meters. the object gains Joules of kinetic energy during this interval

Answer 1

200 J

Step-by-step explanation:

By the law of conservation of energy, the kinetic energy gained by the object during the fall is equal to the loss of gravitational potential energy:

`\Delta K= -\Delta U`

The loss of gravitational potential energy of the object over a distance of 10 m is given by:

`\Delta U=-(mg)(h)`

where

(mg) = 20 N is the weight of the object

h = 10 m is the loss in height

Substituting, we find

`\Delta U = -(20 N)(10 m)=-200 J`

So, the kinetic energy gained by the object is

`\Delta K=-(-200 J)=200 J`