Divide the distance by the speed:
(18 m) / (42 m/s) = 3/7 s ≈ 0.43 s
The velocity of the car at the bottom of the hill=19.8 m/s
mass= 100 kg
height= h=20 m
Velocity at the bottom=V
Using the law of conservation of energy
potential energy at top = kinetic energy at the bottom
m g h= 1/2 m v²
g h= 1/2 v²
9.8 (20)=1/2 V²
V=19.8 m/s
Thus the velocity of car at the bottom of hill=19.8 m/s
The pressure of the atmosphere, when a barometer reads 780 mm Hg. Mercury which a density of 1.36 x 10^4 kg /m^3 is B 1.1 x 10^5 N/m^2
This problem can be solved using the formula below
P = dgh................. Equation 1
Where P = Pressure of the atmosphere, d = density of the mercury, h = height of the mercury, g = acceleration due to gravity.
From the question,
Given: d = 1.36×10⁴ kg/m³, h = 780 mm = 0.78 m,
Constant: g = 10 m/s²
Substitute these values into equation 1
P = (1.36×10⁴)(10)(0.78)
P = 10.608×10⁴ N/m²
P ≈ 1.1×10⁵ N/m²
Hence the right answer is B. 1.1×10⁵ N/m²
Learn more about Pressure here: brainly.com/question/23603188
The first moment of the total cross sectional area taken about the neutral axis must be zero.
As with non-composite beams, the neutral axis (NA) is the location where the bending stress is zero. The location of the NA depends on the relative stiffness and size of each of the material sections.
Generally, the NA location is determined relative to the bottom surface of the beam. However, this is not mandatory, and the location can be relative to any location. If the bottom is used, then the NA axis is a distance "h"
The distance h can be determined by recalling that the stresses through the cross section must be in equilibrium.
learn more about neutral axis from here: brainly.com/question/28167877
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because the car returned to A the velocity is 0
D. The velocity is zero but the speed
