Answer:
The range of wavelengths of the sound is 7692.30 m and 3846.15 m
Explanation:
A bat emits pulses of sound at a frequency between 39 kHz and 78 kHz. It is required to find the range of wavelengths of this sound.
Bat uses ultrasonic waves. It moves with the speed of light.
If f = 39 kHz,
If f = 78 kHz,
So, the range of wavelengths of the sound is 7692.30 m and 3846.15 m.
Answer:
a) a = 3.72 m / s², b) a = -18.75 m / s²
Explanation:
a) Let's use kinematics to find the acceleration before the collision
v = v₀ + at
as part of rest the v₀ = 0
a = v / t
Let's reduce the magnitudes to the SI system
v = 115 km / h (1000 m / 1km) (1h / 3600s)
v = 31.94 m / s
v₂ = 60 km / h = 16.66 m / s
l
et's calculate
a = 31.94 / 8.58
a = 3.72 m / s²
b) For the operational average during the collision let's use the relationship between momentum and momentum
I = Δp
F Δt = m v_f - m v₀
F = 
F = m [16.66 - 31.94] / 0.815
F = m (-18.75)
Having the force let's use Newton's second law
F = m a
-18.75 m = m a
a = -18.75 m / s²
Answer:
tan 249 = 2.61
tan 249 = tan (249 - 180) = tan 69 = 2.61
Assuming that the object starts at rest, we know the following values:
distance = 25m
acceleration = 9.81m/s^2 [down]
initial velocity = 0m/s
we want to find final velocity and we don't know the time it took, so we will use the kinematics equation without time in it:
Velocity final^2 = velocity initial^2 + 2 × acceleration × distance
Filling everythint in, we have:
Vf^2 = 0^2 + (2)(-9.81)(-25)
The reason why the values are negative is because they are going in the negative direction
Vf^2 = 490.5
Take the square root of that
Final velocity = 22.15m/s which is answer c
Answer:
First law of thermodynamic state that energy is always conserved, in other word, energy cannot be created or destroyed.
This means that energy can only transfer from one source to another.
For example, the electricity we used to power our phone didn't come from nowhere.
We charge our phone using the energy from the electricity from the outlet.
The outlet gets its energy from the power plant, who generated that energy from burning coal.
The coal they burned got their energy while they were alive as plants.
The plants got their energy from the sun.
The sun got its energy from other cosmic stuff and so on...
My point is that the energy we use will always cycle around. It doesn't come from thin air and it doesn't disappear into thin air either. This help keeps things balance because if energy is created out of thin air then the earth might just blow up. If energy gets erased into thin air then there'll be nothing to fuel life.
