Answer:
Δy = 7.1 cm
Explanation:
The center of mass of a body is defined
= 1 /M ∑
i
Where M is the total mass of the body, m mass of each part and ‘y’ height
Let's apply this equation to our case
We locate the reference system on the shoulders
The height of the arms is at its midpoint
y = -75/2 = 37.5 cm
With arms down
= 1/70 (63 y₀ - 3.5 37.5 - 3.5 37.5)
= 1/70 (63 y)₀ - 7 37.5)
With arms up
’= 1/70 (63 y₀ + 3.5 y + 3.5 y)
’= 1/70 (63y₀ + 7 35.5)
let's subtract the two equations
’ - = 1/70 2 (7 35.5)
Δy = ’ - = 2 7 35.5 / 70
ΔY = 7.1 cm
Answer:
correct is d) a ’= g / 2
Explanation:
For this exercise let's use the kinematics equations
On earth
v = v₀ - a t
a = (v₀- v) / T
On planet X
v = v₀ - a' t’
a ’= (v₀-v) / 2T
Let's substitute the land values in plot X
a’= a / 2
Now let's use Newton's second law
W = ma
m g = m a
a = g
We substitute
a ’= g / 2
So we see that on planet X the acceleration is half the acceleration of Earth's gravity
<span>When two atoms of the same nonmetal react,they form what we know today as a diatomic molecule.</span>
100kg x bicycle speed = 1400 X 2
bicycle speed = 2800/ 100
bicycle speed = 28 m/s
Answer:
F = 8.6 10⁻¹² N
Explanation:
For this exercise we use the law of conservation of energy
Initial. Field energy with the electron at rest
Em₀ = U = q ΔV
Final. Electron with velocity, just out of the electric field
Emf = K = ½ m v²
Em₀ = Emf
e ΔV = ½ m v²
v =√ 2 e ΔV / m
v = √(2 1.6 10⁻¹⁹ 51400 / 9.1 10⁻³¹)
v = √(1.8075 10¹⁶)
v = 1,344 10⁸ m / s
Now we can use the equation of the magnetic force
F = q v x B
Since the speed and the magnetic field are perpendicular the force that
F = e v B
F = 1.6 10⁻¹⁹ 1.344 10⁸ 0.4
For this exercise we use the law of conservation of energy
Initial. Field energy with the electron at rest
Emo = U = q DV
Final. Electron with velocity, just out of the electric field
Emf = K = ½ m v2
Emo = Emf
.e DV = ½ m v2
.v = RA 2 e DV / m
.v = RA (2 1.6 10-19 51400 / 9.1 10-31)
.v = RA (1.8075 10 16)
.v = 1,344 108 m / s
Now we can use the equation of the magnetic force
F = q v x B
Since the speed and the magnetic field are perpendicular the force that
F = e v B
F = 1.6 10-19 1,344 108 0.4
F = 8.6 10-12 N
