Ahorse began running due east and covered 25 km in 4.0 hr. what is the average velocity of the horse?
a) 0.16 km/hr due east
b) 6.25 km/hr due east
c) 16 km/hr due east
d) 100 km/hr due east

B) due east

Explanation:

Conceptual analysis

The average speed (v) is defined as the relationship between the displacement (d)  that a body made and the total time (t) it took to perform it and is calculated by the following formula:

Formula (1)

v: velocity in m/s

d: Displacement (m)

t: Time (s)

Known data

We know the following data

d = 25 km

t = 4.0 hr

Problem development

We replace data in formula (1):

photocells convert light energy to electricity

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force