Answer:
Therefore the ratio of diameter of the copper to that of the tungsten is
Explanation:
Resistance: Resistance is defined to the ratio of voltage to the electricity.
The resistance of a wire is
- directly proportional to its length i.e
- inversely proportional to its cross section area i.e
Therefore
ρ is the resistivity.
The unit of resistance is ohm (Ω).
The resistivity of copper(ρ₁) is 1.68×10⁻⁸ ohm-m
The resistivity of tungsten(ρ₂) is 5.6×10⁻⁸ ohm-m
For copper:
......(1)
Again for tungsten:
........(2)
Given that 
and 
Dividing the equation (1) and (2)
[since and ]
Therefore the ratio of diameter of the copper to that of the tungsten is
Answer:
23.52 m/s
Explanation:
The following data were obtained from the question:
Time taken (t) to reach the maximum height = 2.4 s
Acceleration due to gravity (g) = 9.8 m/s²
Initial velocity (u) =..?
At the maximum height, the final velocity (v) is zero. Thus, we can obtain how fast the rock (i.e initial velocity)
was thrown as follow:
v = u – gt (since the rock is going against gravity)
0 = u – (9.8 × 2.4)
0 = u – 23.52
Collect like terms
0 + 23.52 = u
u = 23.52 m/s
Therefore, the rock was thrown at a velocity of 23.52 m/s.
Decibel - the decibel is a relative unit of measurement equal to one 10th of a bel
Answer:
110 m
Explanation:
Draw a free body diagram of the car. The car has three forces acting on it: normal force up, weight down, and friction to the left.
Sum of the forces in the y direction:
∑F = ma
N − mg = 0
N = mg
Sum of the forces in the x direction:
∑F = ma
-F = ma
-Nμ = ma
Substitute:
-mgμ = ma
-gμ = a
Given μ = 0.40:
a = -(9.8 m/s²) (0.40)
a = -3.92 m/s²
Given that v₀ = 30 m/s and v = 0 m/s:
v² = v₀² + 2aΔx
(0 m/s)² = (30 m/s)² + 2 (-3.9s m/s²) Δx
Δx ≈ 110 m
