Sound travels at approximately 1,100 feet per second (766 miles per hour). Radio waves travel at the speed of light, which is approximately 186,000 miles per second. This means that in the time radio waves travel the length of a football field, light can travel further than all the way around the world.
Answer:
The tension in string is found to be 188.06 N
Explanation:
For the vibrating string the fundamental frequency is given as:
f1 = v/2L
where,
f1 = fundamental frequency = 335 Hz
v = speed of wave
L = length of string = 28.5 cm = 0.285 m
Therefore,
v = f1 2L
v = (335 Hz)(2)(0.285)
v = 190.95 m/s
Now, for the tension:
v = √T/μ
v² = T/μ
T = v² μ
where,
T = Tension
v = speed = 190.95 m/s
μ = linear mass density of string = mass/L = 0.00147 kg/0.285 m = 5.15 x 10^-3 kg/m
Therefore,
T = (190.95 m/s)²(5.15 x 10^-3 kg/m)
<u>T = 188.06 N</u>
Answer: B
Explanation:
Given that an object of mass 2 kg starts from rest and is allowed to slide down a frictionless incline so that its height changes by 20 m.
The parameters given from the question are:
Mass M = 2kg
Height h = 20m
Let g = 9.8m/s^2
At the bottom of the incline plane, the object will experience maximum kinetic energy.
From conservative of energy, maximum K.K.E = maximum P.E
Maximum P.E = mgh
Maximum P.E = 2 × 9.8 × 20 = 392 J
But
K.E = 1/2mv^2
Substitute the values of energy and mass into the formula
392 = 1/2 × 2 × V^2
V^2 = 392
V = sqrt( 392 )
V = 19.8 m/s
V = 20 m/s approximately
The heat is exchanged when two different temperature objects come in contact. The energy gained by an ice block is 2.3 Joules.
<h3>What is temperature?</h3>
Temperature is the degree of hotness and coldness of the object.
A 7g block of ice was added to a coffee cup full of 103.4 grams of water. The water had an initial temperature T₁ = 24.5 C and a final temperature T₂ = 19.2 C after all the ice had melted.
Heat lost by water = Heat gained by ice
Qgain = ms(T₂ -T₁ )
Substituting the value for mass of water m =103.4 g= 0.1034 kg , specific heat of water s = 4.18 kJ/kg and temperature values, we get
Qgain = 0.1034 x 4.18 x (24.5 - 19.2)
Qgain = 2.3 Joules
Thus, the energy gained by an ice block is 2.3 Joules.
Learn more about temperature.
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Answer:
3000 J
Explanation:
Kinetic energy is:
KE = ½ mv²
If m = 15 kg and v = -20 m/s:
KE = ½ (15 kg) (-20 m/s)²
KE = 3000 J