A rock has a mass of 3.1 kg. What is its weight on earth

W = 30.38 N

Explanation:

Given that,

Mass of a rock, m = 3.1 kg

We need to find the weight of the rock on the surface of Earth. Weight of an object is given by :

W = mg

g is the acceleration due to gravity, g = 9.8 m/s²

W = 3.1 kg × 9.8 m/s²

= 30.38 N

So, the weight of the rock on the Earth is 30.38 N.

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

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.