The ball rolled a distance of
d = 12m + 20m.
But the change of position is
x = + 12m - 20m
Answer:
The shortest braking distance is 35.8 m
Explanation:
To solve this problem we must use Newton's second law applied to the boxes, on the vertical axis we have the norm up and the weight vertically down
On the horizontal axis we fear the force of friction (fr) that opposes the movement and acceleration of the train, write the equation for each axis
Y axis
N- W = 0
N = W = mg
X axis
-Fr = m a
-μ N = m a
-μ mg = ma
a = μ g
a = - 0.32 9.8
a = - 3.14 m/s²
We calculate the distance using the kinematics equations
Vf² = Vo² + 2 a x
x = (Vf² - Vo²) / 2 a
When the train stops the speed is zero (Vf = 0)
Vo = 54 km/h (1000m/1km) (1 h/3600s)= 15 m/s
x = ( 0 - 15²) / 2 (-3.14)
x= 35.8 m
The shortest braking distance is 35.8 m
Answer: Yes, on many slate-roofed homes as temperatures change, such as cooling at night or heating during the day, thermal expansion or contraction of the slates may cause movement that in turn causes snapping, popping, or cracking noises, even bangs and clanks or clicks from the roof.
Explanation:
Answer:
E= 4.35*10^6 N/C
Explanation:
Let's find the area charge density of the plate
α= 6.9*10^-6/9*10^-2 = 7.7*10^-5C/m2
Now we can calculate the electric field just of the plate
E =α/2e =7.7*10^-5/2*8.85*10^-12 = 4.35*10^6 N/C
Answer:
The amount of time for the whole journey is 8 hours.
Explanation:
A truck covered 2/7 of a journey at an average speed of 40 mph. Representing 1 the total of the trip traveled, then the rest of the distance traveled is calculated as: 
So if the truck covered the remaining 200 miles at 
, this means that 
of the trip represents the 200 miles. So, to calculate the total distance traveled by the truck, you apply the following rule of three: if of the route represents 200 miles, the integer 1 (which represents the total of the route), how many miles are they?
miles= 280
So the total distance traveled is 280 miles. Since speed is the relationship between the space traveled by an object and the time used for it (
), then if the average of the entire trip was 35 mph and the distance traveled 280 miles, the time is calculated as:
time= 8 h
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The amount of time for the whole journey is 8 hours.</em></u>
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