Answer:
d = 136.7 ft
Explanation:
Because the truck move with uniformly accelerated movement we apply the following formula:
vf²=v₀²+2*a*d Formula (1)
Where:
d:displacement in meters (ft)
v₀: initial speed in ft/s
vf: final speed in ft/s
a: acceleration in ft/s²
Data
v₀ = 44.0 mi/h
1milla = 5280 ft
1h = 3600 s
v₀ = 44*(5280 ft) / (3600 s) = 64.5 ft/s
vf = 0
d = 47.0 ft
Calculation of the acceleration of the truck
We replace data in the formula (1) :
vf²=v₀²+2*a*d
0 = (64.5)²+2*a*(47)
-(64.5)² = (94)*a
a = -(64.5)² / 94
a = - 44.26 ft/s²
The acceleration (a) it's negative (-) because the truck is braking
Calculation of the minimum stopping distance of the truck to v₀ = 75.0 mi/h
v₀ = 75 mi/h = 75* (5280 ft) / (3600s) = 110 ft/s
We replace v₀ = 110 ft/s and a = - 44.26 ft/s² in the formula (1):
vf²=v₀²+2*a*d
0 = (110)²+2*(-44.26)*d
88.52*d = (110)²
d = (110)² / (88.52)
d = 136.7 ft
The formula for GPE is GPE=mgh. M is for mass, G is for acceleration due to gravity (9.8 m/s/s) and H is for the height.
GPE= mgh
GPE= 500 (kg)*9.8 (m/s/s)* 10 (feet)
GPE= 49,000
Answer: (A) 1.5 m
Explanation:
This situation is due to Refraction, a phenomenon in which a wave (the light in this case) bends or changes its direction when passing through a medium with an index of refraction different from the other medium.
In this context, the index of refraction is a number that describes how fast light propagates through a medium or material.
In addition, we have the following equation that states a relationship between the apparent depth and the actual depth :
(1)
Where:
is the air's index of refraction
water's index of refraction.
is the actual depth of water
Now. when is smaller than the apparent depth is smaller than the actual depth. And, when is greater than the apparent depth is greater than the actual depth.
Let's prove it:
(2)
Finally we find the apparent depth of water, which is smaller than the actual depth:
<em>Since the wagon is being pulled down hill with a constant velocity, all the forces of the wagon would be (C) increasing.</em>
<em>You are correct! **</em>