Answer:
If she stands on the North side of a river flowing to the East at 5 mph,
she must head towards the SouthWest to arrive on the South side of the river directly across from her starting point and we have
x^2 + 5^2 = 10^2 where x is her speed directly across the river
x = (75)^1/2 = 8.66 mph towards the South
sin theta = 5 / 10 = 1/2
She must angle the boat at 30 deg from straight South
The sum of the kinetic and potential energies of a system of objects is conserved only when no external force acts on the objects.
<h3>
Conservation of mechanical energy</h3>
The principle of conservation of mechanical energy states that the total mechanical energy of an isolated system (absence of external force) is always constant.
M.A = P.E + K.E
where;
P.E is potential energy
K.E is kinetic energy
Thus, the sum of the kinetic and potential energies of a system of objects is conserved only when no external force acts on the objects.
Learn more about conservation of mechanical energy here: brainly.com/question/24443465
Answer:
Δx = 1.2 m
Explanation:
The CHANGE of spring length) (Δx) can be found using PS = ½kΔx²
Δx = √(2PS/k) = √(2(450)/650) = 1.17669... ≈ 1.2 m
The actual length of the spring is unknown as it varies with material type, construction method, extension or compression, and other variables we have no clue about.