Answer:
resistance of a conductor increases
Explanation:
The resistance of conductors is directly proportional to the temperature of the conductor. This implies that when the temperature of the conductor is increased, the resistance of the conductor increases likewise.
This is applied in the resistance thermometer. Resistance thermometers are useful for accurate temperature measurements at very high or very low temperatures.
Answer: 7.5 rev/s
Explanation:
We are given the angular velocity 
a helicopter's main rotor blades:
However, we are asked to express this in the International Systrm (SI) units. In this sense, the SI unit for time is second (
):
V = [4/3]π r^3 => [dV / dr ] = 4π r^2
[dV/dt] = [dV/dr] * [dr/dt]
[dV/dt] = [4π r^2] * [ dr/ dt]
r = 60 mm, [dr / dt] = 4 mm/s
[dV / dt ] = [4π(60mm)^2] * 4mm/s = 180,955.7 mm/s
Answer:
a) a = 4.57 m/s², b) a = 6.48 m / s²
, c) a = 1.42 m / s²,d) r = 82.3 m
Explanation:
The centripetal acceleration is the acceleration responsible for the change of direction of the acceleration vector and occurs in circular movements, the expression is
a = v² / r
let's apply this precaution to our cases
a) let's calculate
a = 8²/14
a = 4.57 m/s²
b) an automobile at v = 65 km / h (1000 m / 1km) (1 h / 3600 s) =18,055 m/s
let's reduce feet to meters
1 ft = 0.3048 m
r = 165 ft (0.3048 m / 1 ft) = 50.292 m
a = 18,055 2 / 50,292
a = 6.48 m / s²
c) we calculate
a = 1.25²2 / 1.1
a = 1.42 m / s²
d) we look for the radius
a = v² / r
r = v² / a
we reduce
v = 80 km / h (1000 m / 1km) (1h / 3600s) = 22.22 ms
r = 22.22²/6
r = 82.3 m
e) the cenripeta acceleration is used to take the curves on the highway,
Used in centrifuges to separate compounds
It is used in the games of the park of atraccio
Used in CD players and computer hard drives
