Answer:
The resistivity of the material used to make the rod is ρ= 7.5 * 10⁻⁷ Ω.m
Explanation:
R= 0.2 Ω
L= 0.8 m
S= 1.5mm*2mm= 3 mm² = 3 * 10⁻⁶ m²
ρ = (R*S)/L
ρ= 7.5 * 10⁻⁷ Ω.m
Answer:
B
Explanation:
Work done can be said to be positive if the applied force has a component to be in the direction of the displacement and when the angle between the applied force and displacement is positive.
In 1 and 2 work done is positive
Answer:
Explanation:
Acceleration is the time rate of change of velocity.
Acceleration and velocity are vectors
If east and north are the positive directions, the east moving vector is reduced to zero and the north moving vector increases from zero to 4 m/s.
There are 3 hours or 10800 seconds between 10 AM and 1 PM
a1 = √((-4)² + 4²) / 10800 = (√32) / 10800 m/s² ≈ 4.2 x 10⁻⁴ m/s²
There are 14400 seconds between 10 AM and 2 PM
The velocity changes are still the same
a2 = √((-4)² + 4²) / 10800 = (√32) / 14400 m/s² ≈ 3.9 x 10⁻⁴ m/s²
