Answer:
Explanation:
The coordinate sketch for the system is shown in the attached file below. Also, in the cartesian coordinate system, since the height is less than the length and width, we did neglect the height. Thus, we eliminate the height and converted it to a two-dimension.
Answer: Current needed, mA 20 Voltage needed, V AC 6
Explanation: An electric gradient (or field) can exist that is analogous to the situation described above for step and touch potentials. The situation is more complex to analyze in the water because a person in the water assumes different postures and orientations in 3 dimensions (up, down, and sideways—north, south, east, and west). The transthoracic and translimb voltages will vary as the person moves in relation to the orientation (direction) of the electric field.
Answer:
Y = Stress / Strain = (F / A) / (l / L) where l is the change in length
Since L is doubled and A remains the same one would expect l, the change in length to also double so Y remains the same.
As an example think of hanging a weight from a spring and the same weight from a similar spring of twice the length - one would expect the longer spring to show twice the extension of the shorter spring.
Answer:
Explanation:
The velocity of a wave in a string is equal to:
v = √(T / (m/L))
where T is the tension and m/L is the mass per length.
To find the mass per length, we need to find the cross-sectional area of the thread.
A = πr² = π/4 d²
A = π (3.0×10⁻⁶ m)²
A = 2.83×10⁻¹¹ m²
So the mass per length is:
m/L = ρA
m/L = (1300 kg/m³) (2.83×10⁻¹¹ m²)
m/L = 3.68×10⁻⁸ kg/m
So the wave velocity is:
v = √(T / (m/L))
v = √(7.0×10⁻³ N / (3.68×10⁻⁸ kg/m))
v ≈ 440 m/s
The speed of sound in air at sea level is around 340 m/s. So the spider will feel the vibration in the thread before it hears the sound.
