Answer:
Mass of bike = 38 kg.
Explanation:
Kinetic energy is given by the expression,
, where m is the mass and v is the velocity.
Here speed of child riding bike = 6 m/s
Mass of child = 30 kg
Total kinetic energy = 1224 J
Let the mass of bike be, m kg
So, total mass of child and bike = (m + 30) kg
Substituting,

So, mass of bike = 38 kg.
Answer:
Explanation:
The specific heat of gold is 129 J/kgC
It's melting point is 1336 K
It's Heat of fusion is 63000 J/kg
Assuming that the mixture will be solid, the thermal energy to solidify the gold has to be less than that needed to raise the solid gold to the melting point. So,
The first is E1 = 63000 J/kg x 1.5 = 94500 J
the second is E2 = 129 J/kgC x 2 kg x (1336–1000)K = 86688 J
Therefore, all solid is not correct. You will have a mixture of solid and liquid.
For more detail, the difference between E1 and E2 is 7812 J, and that will melt
7812/63000 = 0.124 kg of the solid gold
Answer:
T = 0.03 Nm.
Explanation:
d = 1.5 in = 0.04 m
r = d/2 = 0.02 m
P = 56 kips = 56 x 6.89 = 386.11 MPa
σ = 42-ksi = 42 x 6.89 = 289.58 MPa
Torque = T =?
<u>Solution:</u>
σ = (P x r) / T
T = (P x r) / σ
T = (386.11 x 0.02) / 289.58
T = 0.03 Nm.
Answer: Option (A) is the correct answer.
Explanation:
Convection is a process in which heat transfers from a hotter substance to a colder substance.
As a result, the substance which is less dense will rise and the more denser substance will sink due to the influence of gravity.
Thus, we can conclude that in the given situation substance X will rise due to convection.
<h3><u>Answer</u>;</h3>
= 22°
<h3><u>Explanation</u>;</h3>
- According to Snell's law, the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant. The constant value is called the refractive index of the second medium with respect to the first.
- Therefore; Sin i/Sin r = η
In this case; Angle of incidence = 90° -60° =30°, angle of refraction =? and η = 1.33
Thus;
Sin 30 / Sin r = 1.33
Sin r = Sin 30°/1.33
= 0.3759
r = Sin^-1 0.3759
= 22.08
<u>≈ 22°</u>