Answer:
0.3 seconds approximately
Explanation:
Given that the height of the building is 55.9 m and cement block accidentally falls from rest from the edge of a 55.9-m-high building. The initial velocity of the block will be equal to zero. The final velocity will be achieved by using the formula:
V^2 = U^2 + 2gH
Where g = 9.8 m/s^2
H = 55.9m
V^2 = 0 + 2 × 9.8 × 55.9
V^2 = 1095.64
V = sqrt(1095.64)
V = 33.1 m/s
The velocity When the block is 11.2 m above the ground will be 33.1 m/s and the height h = 11.2 - 1.7 = 9.5 m
The time of escape can be calculated by using the formula;
h = Ut + 1/2gt^2
9.5 = 33.1t + 1/2 × 9.8 × t^2
9.5 = 33.1t + 4.9t^2
4.9t^2 + 33.1t - 9.5
By using quadratic formula to calculate the time, the negative value is ignored and the positive values will be the time the man has to get out of the way.
Please find the attached file for the remaining solution.
Answer:
The second material's index of refraction is 1.17.
Explanation:
Given that,
Refractive index of the material, n = 1.29
Critical angle is 65.9 degrees.
We need to find the second material's index of refraction. We know that at critical angle of incidence, angle of refraction is equal to 90 degrees. Using Snell's law as:
So, the second material's index of refraction is 1.17.
Answer:
(a) (B)
Explanation:
We have given the the speed of the electron =10^6 m/sec
The time period of the electron is given by where r is the Bohr radius, which is equal to
So time period
(A) We know that current
(B) Magnetic moment is given by , where I is current and A is area
So
The amount of thermal energy required to convert 1.75 kg of solid copper at 1358 K to liquid at 1358 K is 360.5 KJ
Q = m *
Q = Thermal energy
m = Mass
= Latent heat of copper
m = 1.75 kg
= 206 KJ / kg
Q = 1.75 * 206
Q = 360.5 KJ
Thermal energy is a type of energy that is responsible for a system's temperature. The flow of thermal energy is called as heat.
Therefore, the amount of thermal energy required is 360.5 KJ
To know more about thermal energy
brainly.com/question/14506133
#SPJ1