Given:
Stopping distance range is d = (65, 70) ft.
The stopping distance, d, obeys this formula.
d = v²/(2μg)
where
v = speed of the vehicle
μ = 0.8, coefficient of static friction under good road conditions
g = acceleration due to gravity, 32.2 ft/s²
Therefore
v = √(2*0.8*32.2*d) = 7.178√d
Test d = 65 ft.
v = 7.178√(65) = 57.87 ft/s = (57.87/88)*60 = 39.5 mph
Test d = 70 ft.
v = 7.178√(70) = 60.05 ft/s = 40.9 mph
To be safe, the lower speed of 39.5 mph is preferred.
Answer: 40 mph
Answer: 9.312 m/s
Explanation:
The friction force (opposite to the motion) is Fa = μ*m*g*cos(α) with μ = kinetic friction. The force that makes the motion is
F = m*g*sin(α).
The Newton's law gives:
F - Fa = m*a
m*g*sin(α) - μ*m*g*cos(α) = m*a
g*sin(α) - μ*g*cos(α) = a so a = 4.335 m/s²
It's a uniformly accelerated motion:
Space
S = 0.5*a*t²
10 = 0.5*a*t²
=> t = 2.148 s
Velocity
V = a*t = 9.312 m/s.
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.
Some of the scientific questions that may be answered through the experiment are:
(1) What are the physical changes that may occur in the solution or the indicator when added with acidic/basic solution?
(2) How much of the indicator is needed in order to bring about a significant physical change in the solution to identify its H+ concentration?
Answer:
1 N
Explanation:
From coulomb's law,
The force of attraction between two charges is inversely proportional to the square of the distance between the charges.
From the question,
Assuming the charges are the same in both case,
F ∝ /r²....................... Equation 1
Fr² = k
F'r'² = Fr²........................... Equation 2
Where F' = First Force, r'² = First distance, F = second force, r² = second distance.
make F the subject of the equation,
F = F'r'²/r².................... Equation 3
Given: F' = 4 N, r' = 3 m, r = 6 m
Substitute into equation 3
F = 4(3²)/6²
F = 36/36
F = 1 N
