Answer:
4 m/s
Explanation:
It doesn't state it clearly in the problem, but I assume that the shores of the river are parallel and the man reaches the other side perpendicular from where he started (see attached image).
There are an infinite number of ways the swimmer can go from point A to point B, but the shortest time is of course a straight line. We know that the net speed along this line is 3 m/s. We also know the swimmer's speed is 5 m/s. Since the net velocity vector is perpendicular to the river's velocity, we can use Pythagorean theorem.
vᵣ² + (3 m/s)² = (5 m/s)²
vᵣ = 4 m/s
The water in the river flows at a speed of 4 m/s.
Answer:
a) (95.4 i^ + 282.6 j^) N
, b) 298.27 N 71.3º and c) F' = 298.27 N θ = 251.4º
Explanation:
a) Let's use trigonometry to break down Jennifer's strength
sin θ = Fjy / Fj
cos θ = Fjx / Fj
Analyze the angle is 32º east of the north measuring from the positive side of the x-axis would be
T = 90 -32 = 58º
Fjy = Fj sin 58
Fjx = FJ cos 58
Fjx = 180 cos 58 = 95.4 N
Fjy = 180 sin 58 = 152.6 N
Andrea's force is
Fa = 130.0 j ^
We perform the summary of force on each axis
X axis
Fx = Fjx
Fx = 95.4 N
Axis y
Fy = Fjy + Fa
Fy = 152.6 + 130
Fy = 282.6 N
F = (95.4 i ^ + 282.6 j ^) N
b) Let's use the Pythagorean theorem and trigonometry
F² = Fx² + Fy²
F = √ (95.4² + 282.6²)
F = √ (88963)
F = 298.27 N
tan θ = Fy / Fx
θ = tan-1 (282.6 / 95.4)
θ = tan-1 (2,962)
θ = 71.3º
c) To avoid the movement they must apply a force of equal magnitude, but opposite direction
F' = 298.27 N
θ' = 180 + 71.3
θ = 251.4º
C)Wavelength
It has a low frequency electromagnetic radiation that's used to transmit information.