Answer:
Amplitude is decreased by a factor of 
if intensity is decreased by a factor of 3.
Explanation:
Intensity of a sound wave is directly proportional to the square of its amplitude.
Therefore, if intensity is 
and amplitude is 
, then
, where, 
is constant of proportionality.
Now, if intensity of sound wave is decreased by a factor of 3. So,
New intensity is, 
Plug in 
for . This gives,
Therefore, amplitude is decreased by a factor of .
Answer:
The acceleration of the refrigerator is 
Explanation:
The expression of the equation of the net force acting on the refrigerator is as follows;
F-f= ma
Here, F is the applied force, f is the force of friction, m is the mass and a is the acceleration.
It is given in the problem that you're having a hard time pushing a refrigerator having mass 355 kg across the kitchen floor. The force of your own push is 993 N. The force of friction opposing your own push is 973 N.
Put F= 993, f= 973 N and m = 355 kg in the above expression of the equation to calculate the acceleration of the refrigerator.
993 - 973 = (355)a
20 = 355 a
Therefore, the acceleration of the refrigerator is .
Answer:
The gravitational potential energy the barbells have at the maximum height, is P.E. = 3680·h J = 1.10 × 10⁴ units
Where;
h = The maximum height to which he lifts the barbells
Explanation:
The given parameters are;
The amount of work done by the championship lifter in lifting the weight, W = 1.10 × 10⁴ units
The weight of the barbells lifted by the championship lifter, N = 3680 N
The gravitational potential energy, P.E., the barbells had at their maximum height of lift is given as follows;
P.E. = m × g × h
Where;
m = The mass of the barbells;
g = The acceleration due to gravity = 9.8 m/s²
h = The maximum height to which the barbells are lifted by the championship weight lifter
m × g = The weight of the barbells = 3680 N
∴ P.E. = 3680 N × h = 3680·h J
By the conservation of energy principle, work done by the championship weight lifter = The maximum gravitational potential energy gained by the barbell = The gravitational potential energy at the maximum height, P.E.
∴ The gravitational potential energy the barbells have at the maximum height, P.E. = 3680·h J = W = 1.10 × 10⁴ units
Explanation:
power of the bulb = 100w=0.1kw
power consumption when the bulb is used for 30 days ( 30 *24 = 720 hours) =0.1*720=72kwh
cost to run the bulb for 30 days = 72*0.18
= $12.96
Answer is $12.96..................
<span>The first law, also known as Law of Conservation of Energy, states that energy cannot be created or destroyed in an isolated system. The second law of thermodynamics states that the entropy of any isolated system always increases. hope this helps you!</span>
