You toss a 0.40-kg ball at 9.0 ms/ to a 14-kg dog standing on an iced-over pond. The dog catches the ball and begins to slide on
1 answer:
Answer:
a) = 0.25 m / s b) u = 0.25 m / s
Explanation:
a) To solve this problem let's start with the conservation of the moment, for this we define a system formed by the ball plus the dog, in this case all the forces are internal and the moment is conserved
We will write the data
m₁ = 0.40 kg
v₁₀ = 9.0 m / s
m₂ = 14 kg
v₂₀ = 0
Initial
po = m₁ v₁₀
Final
= (m₁ + m₂) vf
po = pf
m₁ v₁₀ = (m₁ + m₂)
= v₁₀ m₁ / (m₁ + m₂)
= 9.0 (0.40 / (0.40 +14)
= 0.25 m / s
b) This is the reference frame of the center of mass of the system in this case the speed of this frame is the speed of the center of mass
u = 0.25 m / s
In the direction of movement of the ball
c) Let's calculate the kinetic energy in both moments
Initial
K₀ = ½ m₁ v₁₀² +0
K₀ = ½ 0.40 9 2
K₀ = 16.2 J
Final
= ½ (m₁ + m₂)
2
= ½ (0.4 +14) 0.25 2
= 0.45 J
ΔK = K₀ -
ΔK = 16.2-0.445
ΔK = 1575 J
These will transform internal system energy
d) In order to find the kinetic energy, we must first find the velocities of the individual in this reference system.
v₁₀’= v₁₀ -u
v₁₀’= 9 -.025
v₁₀‘= 8.75 m / s
v₂₀ ‘= v₂₀ -u
v₂₀‘= - 0.25 m / s
‘=
- u
= 0
Initial
K₀ = ½ m₁ v₁₀‘² + ½ m₂ v₂₀‘²
Ko = ½ 0.4 8.75² + ½ 14.0 0.25²
Ko = 15.31 + 0.4375
K o = 15.75 J
Final
= ½ (m₁ + m₂) vf’²
= 0
All initial kinetic energy is transformed into internal energy in this reference system
You might be interested in
Answer:
Explanation:
1) for a given n value the l value can be from 0 to n-1
So if n= 5 it can take 0,1,2,3,4
i.e it can take 5 values
2)for an electron with l =3
it can be from -3 -2 -1 0 1 2 3
i.e it can take 7 values
3) n = 3 !!
l = 0 , 1 , 2
for l=0 , m = 0 total = 1
for l= 1 ,m = -1,0,1 total = 3
for l = 2, m=-2,-1,0,1,2 total = 5
5+3+1 = 9
total possible states = 9 * 2 = 18
Answer is 168
4)given l=3 and n=3
orbital quantum number cannot be equal to principal quantum number
its max value is l-1 only
5)L = sqrt(l(l+1))x h'
for it to be max l should be max
for n = 3 max l value is 2
therfore it is sqrt(2(2+1)) x h'
this is the answer
Answer:
The third charged particle must be placed at x = 0.458 m = 45.8 cm
Explanation:
To solve this problem we apply Coulomb's law:
Two point charges (q₁, q₂) separated by a distance (d) exert a mutual force (F) whose magnitude is determined by the following formula:
Formula (1)
F: Electric force in Newtons (N)
K : Coulomb constant in N*m²/C²
q₁, q₂: Charges in Coulombs (C)
d: distance between the charges in meters (m)
Equivalence
1μC= 10⁻⁶C
1m = 100 cm
Data
K = 8.99 * 10⁹ N*m²/C²
q₁ = +5.00 μC = +5.00 * 10⁻⁶ C
q₂= +7.00 μC = +7.00 * 10⁻⁶ C
d₁ = x (m)
d₂ = 1-x (m)
Problem development
Look at the attached graphic.
We assume a positive charge q₃ so F₁₃ and F₂₃ are repulsive forces and must be equal so that the net force is zero:
We use formula (1) to calculate the forces F₁₃ and F₂₃
F₁₃ = F₂₃
We eliminate k and q₃ on both sides
We eliminate 10⁻⁶ on both sides
We solve the quadratic equation:
In the option x₂, F₁₃ and F₂₃ will go in the same direction and will not be canceled, therefore we take x₁ as the correct option since at that point the forces are in opposite way .
x = 0.458m = 45.8cm
