An object is released from rest on a planet that has no atmosphere. the object falls freely for 2.31 m in the first second. what is the magnitude of the acceleration due to gravity on the planet? answer in units of m/s^2 .

s=1/2 a t^2

2.31 = 0.5xa

a=4.62m/s^2

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.

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray