A particle's velocity is given by vy(t) = −atj, where a = 0.765 m/s2 is a constant. (b) Find the particle's velocity at
t = 0,

t = 19.0 s,
and
t = 5.20 min.
(Express your answer in vector form.)
(c) Find the particle's speed at
t = 0,

t = 19.0 s,
and
t = 5.20 min.

d. learned preferences i believe is your answer

im sorry i dont know

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.