Answer:
infinity
Explanation:
Given that
Resistance = R
Resistivity = ρ
Length = L
Diameter = d
The resistance of wire R given as
A=Area
Now by putting the value of A
When d tends to infinity then d² will also tends to infinity.
So when d tends to zero then the resistance tends to infinity.
Therefore answer is ---
infinity
Answer:
C.
Explanation:
Let initial charges on both spheres be,
When the sphere C is touched by A, the final charges on both will be,
#Now, when C is touched by B, the final charges on both of them will be:
Now the force between A and B is calculated as:
Hence the electrostatic force becomes 3F/8
Answer
Radius of the wheel r = 2.1 m
Moment of inertia I = 2500 Kg m²
Tangential force applied F = 18 N
Time interval t = 16 s
Initial angular speed ω1 = 0
Final angular speed ω2 = ?
Let α be the angular acceleration.
Torque applied τ = Iα
F r = Iα
Angular acceleration α = F r/I
=
= 0.015 rad/s²
(a)From rotational kinematic relation
Final angular speed ω₂ = ω₁ + αt
= 0 + (0.015 rad/s^2 * 16 s)
= 0.24 rad/s
(b) Work done W = 0.5 Iω₂² - (1/2)Iω₁²
= 0.5*( 2500 Kg m²)(0.24 rad/s)^2 - 0
= 72 J
(c) Average power supplied by the child P = W/t =
= 4.5 watt