Answer:
Option D.
Explanation:
The correct answer is Option D.
The shrinkage of the bridge material is because of thermal contraction.
Thermal contraction and thermal expansion are the phenomena of the bridge material which takes place due to the change in temperature of the atmosphere.
When the temperature of the surrounding increases expansion of the bridge material takes place and when temperature decreases the contraction of the material takes place.
This phenomenon sometimes damages the structure because due to continuous expansion and contraction of materials strength of the bridge decreases.
Answer:A
Explanation:
Explanation:
Given that,
Gravitational force = 600 N
Frictional force = 25 N
Pulled by the Force = 250 N
We know that,
The gravitational force in downward and normal force act in upward. the frictional force in left side and the box pulled by the force to the right side.
The balance equation is along y-axis
The box will not move in y-axis therefore, the net force in the y-axis will be zero.
Hence, The net force in the y-direction will be zero.
Answer:
Animal 1 because it takes 3s to go 25 meters 3.5s to go 50 meters and 5s to go 75 meters while the others take longer.
Explanation:
Answer:
Explanation:
Let hotter star has surface area of A . The cooler star would have surface area 9 times that of hotter star ie 9A , because its radius is 3 times hot star. Let temperature of hot star be T ₁.
Total radiant energy is same for both the star
Using Stefan's formula of black body radiation,
For cold star E = 9A x σ T⁴
For hot star E = A x σ T₁⁴
A x σ T₁⁴ = 9A x σ T⁴
T₁⁴ = (√3)⁴T⁴
T₁ = √3T .
b )
Let the peak intensity wavelength be λ₁ and λ₂ for cold and hot star .
As per wein's law
for cold star , λ₁ T = b ( constant )
for hot star λ₂ √3T = b
dividing
λ₁ T / λ₂ √3T = 1
λ₂ / λ₁ = 1 / √3
The wind speed is 20
the plane is 430mph in still air