Answer: 140 m
Explanation:
Let's begin by stating clear that motiont is the change of position of a body at a certain time. So, during this motion, the balloon will have a trajectory and a displacement, being both different:
The<u> trajectory</u> is <u>the path followed by the body, the distance it travelled</u> (is a scalar quantity).
The displacement is <u>the distance in a straight line between the initial and final position</u> (is a vector quantity).
So, according to this, the distance the balloon traveled during the first 45 s (its trajectory) is 140 m.
But, if we talk about displacement, we have to draw a straight line between the initial position of the balloon (point 0) to its final position (point 90 m). Being its displacement 95 m.
Answer:
r= 2.17 m
Explanation:
Conceptual Analysis:
The electric field at a distance r from a charge line of infinite length and constant charge per unit length is calculated as follows:
E= 2k*(λ/r) Formula (1)
Where:
E: electric field .( N/C)
k: Coulomb electric constant. (N*m²/C²)
λ: linear charge density. (C/m)
r : distance from the charge line to the surface where E calculates (m)
Known data
E= 2.9 N/C
λ = 3.5*10⁻¹⁰ C/m
k= 8.99 *10⁹ N*m²/C²
Problem development
We replace data in the formula (1):
E= 2*k*(λ/r)
2.9= 2*8.99 *10⁹*(3.5*10⁻¹⁰/r)
r =( 2*8.99 *10⁹*3.5*10⁻¹⁰) / (2.9)
r= 2.17 m
Inelastic.
If it was elastic, they'd bump right off each other. But since they've been locked, or stuck together, this is inelastic.
Answer:
3. none of these
Explanation:
The rotational kinetic energy of an object is given by:
where
I is the moment of inertia
is the angular speed
In this problem, we have two objects rotating, so the total rotational kinetic energy will be the sum of the rotational energies of each object.
For disk 1:
For disk 2:
so the total energy is
So, none of the options is correct.
In this system we have the conservation of angular momentum: L₁ = L₂
We can write L = m·r²·ω
Therefore, we will have:
m₁ · r₁² · ω₁ = m₂ · r₂² · ω₂
The mass stays constant, therefore it cancels out, and we can solve for ω<span>₂:
</span>ω₂ = (r₁/ r₂)² · ω<span>₁
Since we know that r</span>₁ = 4r<span>₂, we get:
</span>ω₂ = (4)² · ω<span>₁
= 16 </span>· ω<span>₁
Hence, the protostar will be rotating 16 </span><span>times faster.</span>
