Answer:
The terminal speed of this object is 12.6 m/s
Explanation:
It is given that,
Mass of the object, m = 80 kg
The magnitude of drag force is,

The terminal speed of an object is attained when the gravitational force is balanced by the gravitational force.



On solving the above quadratic equation, we get two values of v as :
v = 12.58 m/s
v = -15.58 m/s (not possible)
So, the terminal speed of this object is 12.6 m/s. Hence, this is the required solution.
Answer:
The temperature of the windings are 60.61 °C
Explanation:
Step 1: Data given
Resistance = 50 Ω
Temperature = 20.0 °C
After the motor has run for several hours the resistance rises to 58Ω.
Step 2: Calculate the new temperature
Formula: R = Rref(1 + α(T-Tref))
⇒with α = temperature coëfficiënt of Cupper at 20 °C = 0.00394/°C
⇒with Tref = reference temperature = 20°C
⇒with T = end temperature = TO BE DETERMINED
⇒with R = resistance at end temperature = 58Ω
⇒with Rref = resistance at reference temperature = 50 Ω
==> T = (R/Rref - 1)/α + Tref
T = (58/50) - 1 )/ 0.00394 + 20
T = 60.61 °C
The temperature of the windings are 60.61 °C
Answer:
A.B = -38
Explanation:
A = 2i + 9j and B = -i - 4j.
So, A.B = (2i + 9j).(-i - 4j)
= 2i.(-i) + 2i.(-4j) + 9j.(-i) + 9j.(-4j)
= -2i.i - 8i.j - 9j.i - 36j.j
since i.i = 1, j.j = 1, i.j = 0 and j.i = 0, we have
A.B = -2(1) - 8(0) - 9(0) - 36(1)
A.B = -2 - 0 - 0 - 36
A.B = -38
It's the external shape of the crystal. You can determine how developed the crystals are and it'll help identify what species of mineral it is. Hope that helped