4. Jed drops a 10 kg box off of the Eiffel Tower. After 2.6 seconds, how fast is the box moving? (Neglect air resistance.)
1 answer:
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Answer:
Explanation:
BMI= weight/(height × height) ; weight in kilogram and height in metter
= 58kg / (1.61m × 1.61m )
= (58/ 2.5921) kg/
= 22.375 kg/
≈ 22.4 kg/
Answer:
a) ΔV₁ = 21.9 V, b) U₀ = 99.2 10⁻¹² J, c) U_f = 249.9 10⁻¹² J, d) W = 150 10⁻¹² J
Explanation:
Let's find the capacitance of the capacitor
C =
C = 8.85 10⁻¹² (8.00 10⁻⁴) /2.70 10⁻³
C = 2.62 10⁻¹² F
for the initial data let's look for the accumulated charge on the plates
C =
Q₀ = C ΔV
Q₀ = 2.62 10⁻¹² 8.70
Q₀ = 22.8 10⁻¹² C
a) we look for the capacity for the new distance
C₁ = 8.85 10⁻¹² (8.00 10⁻⁴) /6⁴.80 10⁻³
C₁ = 1.04 10⁻¹² F
C₁ = Q₀ / ΔV₁
ΔV₁ = Q₀ / C₁
ΔV₁ = 22.8 10⁻¹² /1.04 10⁻¹²
ΔV₁ = 21.9 V
b) initial stored energy
U₀ =
U₀ = (22.8 10⁻¹²)²/(2 2.62 10⁻¹²)
U₀ = 99.2 10⁻¹² J
c) final stored energy
U_f = (22.8 10⁻¹²) ² /(2 1.04 10⁻⁻¹²)
U_f = 249.9 10⁻¹² J
d) the work of separating the plates
as energy is conserved work must be equal to energy change
W = U_f - U₀
W = (249.2 - 99.2) 10⁻¹²
W = 150 10⁻¹² J
note that as the energy increases the work must be supplied to the system
Answer: N = Mgcos(theta)
Therefore, the Normal reaction force is equal to Mgcos(theta)
Explanation:
See attached for a sketch.
From the attachment.
.
N = normal reaction force on block
W = weight of the block
theta = angle of the inclined plane to the horizontal
From the sketch, we can see that
N is equal in magnitude but opposite direction to Wy
N = Wy
And
Wy = Wcos(theta)
Wx = Wsin(theta)
Then,
N = Wy = Wcos(theta)
But W = mass × acceleration due to gravity = mg
N = Mgcos(theta)
Therefore, the Normal reaction force is equal to Mgcos(theta)
