A closed system is a system that is completely isolated from its environment. The physical universe, as we currently understand it, appears to be a closed system. An open system is a system that has flows of information, energy, and/or matter between the system and its environment, and which adapts to the exchange.
D makes the most sense, but you just have to put two and two together and go with your gut feeling, first cross out the answers that don't make sense (A didnt make sense) and go from there! I hope the little bit above me helped you answer or decide :) Good luck!
Answer
given,
frequency from Police car= 1240 Hz
frequency of sound after return = 1275 Hz
Calculating the speed of the car = ?
Using Doppler's effect formula
Frequency received by the other car
..........(1)
u is the speed of sound = 340 m/s
v is the speed of the car
Frequency of the police car received

now, inserting the value of equation (1)


1.02822(340 - v) = 340 + v
2.02822 v = 340 x 0.028822
2.02822 v = 9.799
v = 4.83 m/s
hence, the speed of the car is equal to v = 4.83 m/s
The components of the net force on the cart is determined as 67.66 N.
<h3>
Component of net force on the cart</h3>
The component of net force on the cart is determined by resolving the forces into x and y -components.
T1 = 30 N
T2 = 40 N
T1x = -30cos(0) = 30 N
T1y = 30sin(0) = 0
T2x = 40 x cos(30) = 34.64 N
T2y = 40 x sin(3) = 20 N
∑X = 30 N + 34.64 N = 64.64 N
∑Y = 0 + 20 N = 20 N
<h3>Resultant force</h3>
R = √(64.64² + 20²)
R = 67.66 N
Learn more about net force here: brainly.com/question/25239010
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Answer:
23.1 N/C
Explanation:
OP = 3 m , OQ = 4 m

q = - 8 nC, Q = 75 nC
Electric field at P due to the charge Q is

Electric field at P due to the charge q is

According to the diagram, tanθ = 3/4
Resolve the components of E1 along x axis and along y axis.
So, Electric field along X axis, Ex = - E1 Cos θ
Ex = - 27 x 4 / 5 = - 21.6 N/C
Electric field along y axis, Ey = E1 Sinθ - E2
Ey = 27 x 3 /5 - 8 = 8.2 N/C
The resultant electric field at P is given by

Hi Jason!☺
The answer is going to be
B, they harm the ozone layer.I have taken the quiz and am 100% sure.
~Elisabeth