Pretty sure it is clockwise if I am not mistaken
Answer:
Explanation:
Average energy contained by a slice of pizza is 860 J .
energy used in lifting 32 kg bar by .50 m = mgh
= 32 x 9.8 x .5 = 156.8 J
efficiency is 25 % , so energy used up = .75 x 156.8 = 117.6 J
So number of times exercise to be repeated to burn off energy of a slice of pizza
= 860 / 117.6
= 7.3 or 7 times .
Answer:
C
Explanation:
To solve this question, we will need to develop an expression that relates the diameter 'd', at temperature T equals the original diameter d₀ (at 0 degrees) plus the change in diameter from the temperature increase ( ΔT = T):
d = d₀ + d₀αT
for the sphere, we were given
D₀ = 4.000 cm
α = 1.1 x 10⁻⁵/degrees celsius
we have D = 4 + (4x(1.1 x 10⁻⁵)T = 4 + (4.4x10⁻⁵)T EQN 1
Similarly for the Aluminium ring we have
we were given
d₀ = 3.994 cm
α = 2.4 x 10⁻⁵/degrees celsius
we have d = 3.994 + (3.994x(2.4 x 10⁻⁵)T = 3.994 + (9.58x10⁻⁵)T EQN 2
Since @ the temperature T at which the sphere fall through the ring, d=D
Eqn 1 = Eqn 2
4 + (4.4x10⁻⁵)T =3.994 + (9.58x10⁻⁵)T, collect like terms
0.006=5.18x10⁻⁵T
T=115.7K
Answer:
E = 2,575 eV
Explanation:
For this exercise we will use the Planck equation and the relationship of the speed of light with the frequency and wavelength
E = h f
c = λ f
Where the Planck constant has a value of 6.63 10⁻³⁴ J s
Let's replace
E = h c / λ
Let's calculate for wavelengths
λ = 4.83 10-7 m (blue)
E = 6.63 10⁻³⁴ 3 10⁸ / 4.83 10⁻⁷
E = 4.12 10-19 J
The transformation from J to eV is 1 eV = 1.6 10⁻¹⁹ J
E = 4.12 10⁻¹⁹ J (1 eV / 1.6 10⁻¹⁹ J)
E = 2,575 eV
