Alex was biking along a 48 mile trail. first half of the time he was biking twice as fast as the second half of the time. if he spent 4 hours on the road, how fast was he biking at first?

The speed in the first part is 16 mph.

Step-by-step explanation:

The total distance is 48 miles. The total time is 4 hours.

In the second part of the trip, he was traveling at speed s for distance d for 2 hours.

In the first part of the trip he was traveling at twice the speed, or 2s, for distance 48 - d, for 2 hours.

speed = distance/time

distance = speed * time

First part of trip:

48 - d = 2s * 2

d + 4s = 48   Equation 1

Second part of the trip:

d = s * 2

d = 2s    Equation 2

Equations 1 and 2 form a system of equations in two unknowns, d and s.

d + 4s = 48

d = 2s

Substitute 2s for d in equation 1.

2s + 4s = 48

6s = 48

s = 8

The speed in the second part is 8 mph.

The speed in the first part is 2s = 2(8) = 16.

The speed in the first part is 16 mph.

Check:

d = 2s = 2(8) = 16

48 - d = 48 - 16 = 32

The second part is 16 miles. The first part is 32 miles.

16 miles at 8 mph takes 2 hours.

32 miles at 16 mph takes 2 hours.

2 hours + 2 hours = 4 hours.

Our answer is correct.

The speed in the first part is 16 mph.

The speed in the first part is 16 mph.  

Step-by-step explanation:

The total distance is 48 miles. The total time is 4 hours.  

In the second part of the trip, he was traveling at speed s for distance d for 2 hours.  

In the first part of the trip he was traveling at twice the speed, or 2s, for distance 48 - d, for 2 hours.  

speed = distance/time  

distance = speed * time  

First part of trip:  

48 - d = 2s * 2  

d + 4s = 48   Equation 1  

Second part of the trip:  

d = s * 2  

d = 2s    Equation 2  

Equations 1 and 2 form a system of equations in two unknowns, d and s.  

d + 4s = 48  

d = 2s  

Substitute 2s for d in equation 1.  

2s + 4s = 48  

6s = 48  

s = 8  

The speed in the second part is 8 mph.  

The speed in the first part is 2s = 2(8) = 16.  

The speed in the first part is 16 mph.  

Check:  

d = 2s = 2(8) = 16  

48 - d = 48 - 16 = 32  

The second part is 16 miles. The first part is 32 miles.  

16 miles at 8 mph takes 2 hours.  

32 miles at 16 mph takes 2 hours.  

2 hours + 2 hours = 4 hours.  

Our answer is correct.

The speed in the first part is 16 mph

you forgot the options, but i found them anyways, the correct answer is "john wilson believes that words and actions based on the intellect are superior to those based on emotions".

john wilson is depicted as an extremely intelligent man. the point of the excerpt is to make a sort of distinction between emotional and rational intelligence. he happens to have both attributes, but he clearly favors his intellectual gifts. at the same time, because of his religious background, he's a little bit conflicted with this and it makes him ashamed.

hope this !

the population of other specie of birds will decline or other specie of birds will find some alternate source of food to survive.

explanation:

according to the competitive exclusion principle, which is also known as gause's law, two specie living in the same niche and feeding on the same resource cannot co-exist stably.

as we have well studied the theory of natural selection which states that only those organisms survive which have better tendency to compete for food and adapt to the environmental conditions.

coming towards the question, what wi ll happen when one species outcompetes the other for the small fish , the other specie will not get enough food and will start to die or decline in population. eventually either other specie needs to find another alternative food source for itself or migrate at some other location where there is less competition otherwise it will just not exist anymore at that niche.

hope it !