Which of the following objects has the greatest kinetic energy?

a baseball flying through the air at 20 miles per hour
a baseball flying through the air at 90 miles per hour
a baseball sitting on the ground
a baseball flying through the air at 45 miles per hour

A baseball flying through the air at 90 miles per hour.

Explanation:

Kinetic energy is a type of energy that an object has because of its motion. In this example, a baseball that is flying through the air would have kinetic energy because of this movement. In order to move this object, a force needs to be applied to it. In order for us to know the kinetic energy of an object, we have to look at both the mass and the speed. In this case, this ball would have the greatest kinetic energy because it has the greatest speed.

cell differentiation  is how generic embryonic  cells  become specialized  cells. this occurs  through a process called gene expression. gene expression is the specific combination of genes that are turned on or off (expressed or repressed), and this is what dictates how a  cell  functions.

explanation:

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2