A boy does a work of 800 J is dragging a sack of rice through a distance of 10 m. What is the
magnitude of force applied by the boy?​

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.

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.

prndulum needs thread, weight clock to time swings