Answer:
3.196 m/s
Explanation:
Parameters given:
Mass of Brittany and the skateboard, M = 62 kg
Mass of pumpkin, m = 3.7 kg
Initial speed of Brittany and the skateboard, U = 0 m/s
Final velocity of Brittany, the skateboard and the pumpkin, V = v = 0.18 m/s
We can solve this problem by applying the principle of conservation of momentum.
It states that the total final momentum of a system is equal to the total initial momentum of the system.
M*U + m*u = M*V + m*v
Where u is the initial velocity of the pumpkin.
Since the final velocity of Brittany and the skateboard is equal to the final velocity of pumpkin:
M*U + m*u = (M + m) *v
Solving this to get u:
(62 * 0) + (3.7 * u) = (62 + 3.7) * 0.18
0 + 3.7u = 65.7 * 0.18
3.7u = 11.826
u = 11.826 / 3.7
u = 3.196 m/s
The initial velocity of the pumpkin was 3.196 m/s.
Answer:
The intensity level in the room is 63 dB
Explanation:
To calculate the intensity of sound in the room, we use the equation of definition of decibels
β = 10 log (I / Io) (1)
With “I” the sound intensity and “Io” the threshold intensity 1.0 10⁻⁻¹² W/m²
To calculate the intensity we will use the initial data and remember the power of the emitted sound is constant, in addition that the sound propagates in three-dimensional form or on a spherical surface
I = P/A ⇒ P = I A
The area of a sphere is 4 π r², where I can calculate of 1
β/10 = log (I/Io)
I / Io = 
I = Io 
I = 1 10⁻¹² 10⁽¹⁰⁰/¹⁰⁾ = 1 10⁻¹² 10¹⁰
I = 1.0 10⁻² W
With this we can calculate the intensity for a distance of 20 m
I = 1.0 10⁻² / ( 4π 20²)
I = 2.0 10⁻⁶ W/m²
We have already found the intensity at the point of interest, so we can calculate the intensity in decibels at this point with equation 1
β = 10 log(2.0 10⁻⁶ / 1.0 10⁻¹²)
β = 10 log ( 2 10⁶) = 10 6.3
β = 63 dB
The intensity level in the room is 63 dB
Answer:
The range of characteristic frequencies of electromagnetic radiation that are readily absorbed and emitted by an atom. The atomic spectrum is an effect of the quantized orbits of electrons around the atom
Additional Facts:
- Atomic spectra can also be analyzed to determine the composition of objects
- The frequency depends on the difference in energy between the orbitals. Explaining this phenomenon was crucial to the development of quantum mechanics
- Occurs due to the fact are quantized at specific levels determined by the atomic number
<h2>
Power of cheetah is 5576.85 W = 7.48 hp</h2>
Explanation:
Power is the ratio of energy to time.
Here we need to consider kinetic energy,
Mass, m = 102 kg
Initial velocity = 0 m/s
Final velocity = 16.2 m/s
Time, t = 2.4 s
Initial kinetic energy = 0.5 x Mass x Initial velocity² = 0.5 x 102 x 0² = 0 J
Final kinetic energy = 0.5 x Mass x Final velocity² = 0.5 x 102 x 16.2² = 13384.44 J
Change in energy = Final kinetic energy - Initial kinetic energy
Change in energy = 13384.44 - 0
Change in energy = 13384.44 J
Power = 13384.44 ÷ 2.4 = 5576.85 W = 7.48 hp
Power of cheetah is 5576.85 W = 7.48 hp
Solar Radiation, Orbital Distance, Air Pressure, and the Abundance of water.