The distance covered by car is equal to (assuming it is moving by uniform motion) the product between the car's speed and the time of the car ride, 4 h:
![S_c = v_c t_c](https://tex.z-dn.net/?f=S_c%20%3D%20v_c%20t_c%20)
where
![v_c](https://tex.z-dn.net/?f=v_c%20)
is the car's speed
![t_c = 4 h](https://tex.z-dn.net/?f=t_c%20%3D%204%20h)
is the duration of the car ride
Similarly, the distance covered by train is equal to the product between the train's speed and the duration of the train ride, 7 h:
![S_t = v_t t_t](https://tex.z-dn.net/?f=S_t%20%3D%20v_t%20t_t)
The total distance covered is S=255 km, which is the sum of the distances covered by car and train:
![S=255 km = S_c + S_t](https://tex.z-dn.net/?f=S%3D255%20km%20%3D%20S_c%20%2B%20S_t%20)
which becomes
![255 = 4 v_c + 7 v_t](https://tex.z-dn.net/?f=255%20%3D%204%20v_c%20%2B%207%20v_t)
(1)
we also know that the train speed is 5 km/h greater than the car's speed:
![v_t = 5 + v_c](https://tex.z-dn.net/?f=v_t%20%3D%205%20%2B%20v_c)
(2)
If we put (2) into (1), we find
![255 = 4v_c + 7(5+v_c)](https://tex.z-dn.net/?f=255%20%3D%204v_c%20%2B%207%285%2Bv_c%29)
and if we solve it, we find
![v_c = 20 km/h](https://tex.z-dn.net/?f=v_c%20%3D%2020%20km%2Fh)
![v_t = 25 km/h](https://tex.z-dn.net/?f=v_t%20%3D%2025%20km%2Fh)
So, the car speed is 20 km/h and the train speed is 25 km/h.
a. use increased crop diversity and fewer off the farm resources in order to reduce pressure on resources
Explanation:
A farmer using sustainable agricultural practices will use increased crop diversity and fewer off the farm resources in order to reduce dependency on other resources.
The major goal of sustainable agriculture is to cultivate plants and groom livestock in the best way that won't alter the environment.
- This usually entail the cultivation of different crops.
- Diversity of crops provides the means to sustain and retain soil fertility naturally without having to add fertilizers.
- In animal husbandry, some of wastes are used on farm and the excesses from the farm are used to feed livestock.
- Sustainable agriculture is a practice of self-reliant agriculture without infringing on the environment.
learn more:
Human impact on rainforest brainly.com/question/12095428
#learnwithBrainly
Answer - There are three ways an object can accelerate: a change in velocity, a change in direction, or a change in both velocity and direction.
Try C. a downward gravitational force exerted by Earth
Answer:
C: Variation in the value of g as the pendulum bob moves along its arc.
Explanation:
The formula for period of a simple pendulum is given by;
T = 2π√(L/g)
Where;
L is length
g is acceleration due to gravity
Now, from this period equation, it is clear that the only thing that can affect the period of a simple pendulum are changes to its length and acceleration due to gravity.
Looking at the options, the only one that talks about either the length or gravity as being potential causes of the error is option C