Answer:
697 m
Explanation:
From the question above,
Note: Alice hears the splash of the rock in the well through the help of echo.
Applying,
v = 2x/t........................ Equation 1
Where v = speed of sound, x = depth of the well, t = time.
make x the subject of the formula in equation 1
x = vt/2................... Equation 2.
Given: v = 340 m/s, t = 4.1 s
Substitute these values into equation 2
x = 340(4.1)/2
x = 697 m.
In the first figure, the surface absorbs all colors except for green light, which is reflected: so, the surface will appear as green to our eyes, because green is the only color which is reflected by that surface.
Similarly, in the second figure, the surface absorbs all colors except for blue, and so the surface will appear blue to our eyes.
In the third figure, the surface absorbs all colors, so it will appear black to our eyes (because no colors are reflected, and black=absence of colors).
In the fourth figure, all colors are reflected: this means the surface will appear white to our eyes (white= sum of all colors).
Answer:
Part a)
a = - 8.45 m/s/s
Part b)
Part c)
Explanation:
Part a)
when car apply brakes then the friction force on the car in front of us is given as
here we need to find deceleration due to friction
Part b)
Braking distance of the car is the distance that it move till it stops
so we will have
Part c)
Since we know that average reaction time for human is 0.424 s
now we know that during reaction time our car will travel at uniform speed
so we will have
I believe the answer is C. Positive, since it is a sustainable plan to use a renewable source hope this helps :)
