A snowboarder drops from rest into a halfpipe of radius R and slides down its frictionless surface to the bottom (a) Show that the snowboarder's speed at the bottom of the halfpipe is
v = 2gR (use conservation of energy)
(b) Show that the snowboarder's centripetal acceleration at the bottom is
ac = 2g (Apply the expression for centripetal acceleration)
(c) Show that the normal force on the snowboarder at the bottom of the halfpipe has a magnitude of 3mg (Use Newton's second law of motion)

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.

c) power lifting, will be your answer.

,

deku ❤

friction

explanation:

they us to move forward and backwards