Answer:
Explanation:
For sound level in decibel scale the relation is
dB = 10 log I / I₀ where I₀ = 10⁻¹² and I is intensity of sound whose decibel scale is to be calculated .
Putting the given values
61 = 10 log I / 10⁻¹²
log I / 10⁻¹² = 6.1
I = 10⁻¹² x 10⁶°¹

intensity of sound of 5 persons


= 10log 5 x 10⁶°¹
= 10( 6.1 + log 5 )
= 67.98
sound level will be 67.98 dB .
Answer:
Option D. ²³⁹₉₃Np
Explanation:
Let the unknown be ʸₓA.
Thus, the equation becomes:
²³⁹₉₂U —> ⁰₋₁e + ʸₓA
Next, we shall determine the x, y and A. This can be obtained as follow:
92 = –1 + x
Collect like terms
92 + 1 = x
93 = x
x = 93
239 = 0 + y
239 = y
y = 239
ʸₓA => ²³⁹₉₃A => ²³⁹₉₃Np
Thus, the complete equation is:
²³⁹₉₂U —> ⁰₋₁e + ²³⁹₉₃Np
The statements of both students are incorrect.
-- Electrical power, just like mechanical power, is expressed in units of watts.
-- 'Coulomb' is the unit of electrical charge.
-- '400 k ohms' means 400,000 ohms of resistance.
-- 'Volt' is the unit of electromotive force (or potential difference).
There are no 'following statements'.
All in all, a very disappointing question.
Answer:
F n = 0.2 N
Explanation:
given,
you are exerting force of 10 N on the ball.
mass of the ball = 1 kg
acceleration due to gravity = 9.8 m/s²
normal force on the ball = ?
normal force is force exerted by the object to counteract the force from other object.
normal force acting on the ball will be
F n = F - mg
F n = 10 - 1 × 9.8
F n = 10 -9.8
F n = 0.2 N
Hence, normal force acting on the ball is equal to 0.2 N
Answer:



Explanation:
<u>Simple Pendulum</u>
It's a simple device constructed with a mass (bob) tied to the end of an inextensible rope of length L and let swing back and forth at small angles. The movement is referred to as Simple Harmonic Motion (SHM).
(a) The angular frequency of the motion is computed as

We have the length of the pendulum is L=0.81 meters, then we have


(b) The total mechanical energy is computed as the sum of the kinetic energy K and the potential energy U. At its highest point, the kinetic energy is zero, so the mechanical energy is pure potential energy, which is computed as

where h is measured to the reference level (the lowest point). Please check the figure below, to see the desired height is denoted as Y. We know that

And

Solving for Y



The potential energy is


The mechanical energy is, then


(c) The maximum speed is achieved when it passes through the lowest point (the reference for h=0), so the mechanical energy becomes all kinetic energy (K). We know

Equating to the mechanical energy of the system (M)

Solving for v

