In 2007, Michael Carter (U. S.) set a world record in the shot put with a throw of 24.77 m. What was the initial speed of the shot if he released it at a height of 2.10 m and threw it at an angle of 38.0o above the horizontal

Explanation:

The horizontal displacement of throw = 24.77 m

vertical displacement of throw = 2.1 m

Let u be the initial speed of throw.

vertical component = u sin38

= .6156 u

horizontal component of speed of throw = u cos 38

= .788 u

Let t be time of flight .

For horizontal displacement

24.77 = .788 u t

t = 24.77 /.788 u

For vertical displacement :--

s = ut + gt²

2.1 = -  .6156 u t + 4.9 t²

=  -.6156 u x (24.77 /.788 u ) + 4.9 x t²

2.1 = - 19.35 + 4.9 t²

21.45 = 4.9 t²

t = 2.1 s

t = 24.77 /.788 u

u =  24.77 /.788 t

= 14.96 m / s

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.