How much work can be done in 30 seconds by a 1000-watt microwave oven?

30000 J

Explanation:

Power is defined as the amount of work done per unit time:

where

P is the power

W is the work done

t is the time taken

In this problem, we know the power of the microwave oven: , and we are asked to find the work done in a time of , so by re-arranging the equation we find:

0.11 m/s and 0.28 m/s should be correct

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.