Answer:
t = 1.27 x 10⁹ s
Explanation:
First, we will find the volume of the wire:
Volume = V = AL
where,
A = Cross-sectional area of wire = πr² = π(1 cm)² = π(0.01 m)² = 3.14 x 10⁻⁴ m²
L = Length of wire = 150 km = 150000 m
Therefore,
V = 47.12 m³
Now, we will find the number of electrons in the wire:
No. of electrons = n = (Electrons per unit Volume)(V)
n = (8.43 x 10²⁸ electrons/m³)(47.12 m³)
n = 3.97 x 10³⁰ electrons
Now, we will use the formula of current to find out the time taken by each electron to cross the wire:
where,
t = time = ?
I = current = 500 A
q = total charge = (n)(chareg on one electron)
q = (3.97 x 10³⁰ electrons)(1.6 x 10⁻¹⁹ C/electron)
q = 6.36 x 10¹¹ C
Therefore,
<u>t = 1.27 x 10⁹ s</u>
Answer:
The magnitude of the average angular acceleration is calculated as 
Explanation:
Maximum speed that can be attained by the disk, 
= 10,000 rpm
Speed of spinning of the disk, N = 7570 rpm
Time taken to come to rest, t = 0.435 s
Now,
The initial angular velocity is given by:
Final angular velocity, 
The average angular acceleration of the disk can be computed by using the kinematic eqn:
As a rocket increases height and slows down, it gains more and more potential energy and loses more and more kinetic energy. Potential energy is store energy (usually determined by height), and kinetic energy increases as speed increases.
Answer:
52.49 Kg
Explanation:
Let m1 and v1 denote your mass and velocity respectively
Let m2 and v2 denote your friends mass and velocity respectively
Kinetic energy is given by
Since your kinetic energies are the same hence
and making m2 the subject then
Since v2 is v1+0.28v1=1.28v1
Substituting m1 for 86 Kg
