Answer:
laws of motion relate an object’s motion to the forces acting on it. In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction.
Answer:
Structural adaptation
Explanation:
When any physical body part of an organism helps it in surviving, then this mechanism of survival is called a structural adaptation. For example short tail of penguins helps them in balancing on their heels and tails due to which they are able to reduce heat released from their feet. Thus, any physical parts of an organism that helps them in coping with the surrounding physical environment /predators are refereed to as a mode of structural adaptation.
In this item, we let x be the rate of the boat in still water and y be the rate of the current.
Upstream. When the boat is going upstream, the speed in still water is deducted by the speed of the current because the boat goes against the water. The distance covered is calculated by multiplying the number of hours and the speed.
(x - y)(3) = 144
Downstream. The speed of the boat going downstream is equal to x + y because the boat goes with the current.
(x + y)(2) = 144
The system of linear equations we can use to solve for x is,
3x - 3y = 144
2x + 2y = 144
We use either elimination or substitution.
We solve for the y of the first equation in terms of x,
y = -(144 - 3x)/3
Substitute this to the second equation,
2x + 2(-1)(144 - 3x)/3 = 144
The value of x from the equation is 60
<em>ANSWER: 60 km/h</em>
Explanation:
The net force would be upwards since the kangaroo would have to overcome gravity to jump
