Walking along the beach, you notice that a new wave reaches the shore every 3.8 s , and you estimate the wave crests to be 2.5 m apart. at what wave speed c are the waves moving?

Explanation:

1. Data:

a) period = 3.8 s

b) λ = 2.5 m

c) c = ?

2. Physical principles and formula:

              distance     = speed     ×      time

            wavelength = speed      ×       T

                      λ         =      c         ×       T

                 meter      = (meter/second)  ×   second

                      m        =               (m /s)    ×     s

3. Solution:

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.

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.