Explanation:
We'll need two equations.
v² = v₀² + 2a(x - x₀)
where v is the final velocity, v₀ is the initial velocity, a is the acceleration, x is the final position, and x₀ is the initial position.
x = x₀ + ½ (v + v₀)t
where t is time.
Given:
v = 47.5 m/s
v₀ = 34.3 m/s
x - x₀ = 40100 m
Find: a and t
(47.5)² = (34.3)² + 2a(40100)
a = 0.0135 m/s²
40100 = ½ (47.5 + 34.3)t
t = 980 s
Let
V the speed of the girl per step
v the speed of the escalator per step
L the length between ground and floor in number of steps
V*60+v*60=L => V+v=L/60
V*90-v*90=L => V-v=L/90
By adding the equations V+v=L/60 and V-v=L/90 we get:
2V=L(3+2)/180
V=5L/360
V = L/72
Time to climb (in steps) with v=0 (escalator standing still) is:
V*t=L
t = L/V
t = L/(L/72)
t =72 steps
The girl will count 72 steps.
Answer:
a I think hope this helps
We are ask to know where is the location of the coal bed, in
this given sentence when you need to analyze every words just to know where is
the coal bed located.
To my understanding the coal bed is located just above the
highest piece of sandstone seen in the soil.
Answer:
-1.82m/s²
Explanation:
Given that the reaction time (t) is negligible and car brakes with constant acceleration.
Initial Velocity (u) = 20m/s
Distance(d) from Intersection when light turns red = 110m
Hence, the magnitude of braking acceleration that will bring the car to rest at exactly the intersection :
Using the motion equation:
v² = u² + 2as
Where v = final velocity at the intersection
u = initial velocity ; s = distance to intersection ; a = acceleration of the car
Exactly at the intersection ; v = 0
0 = 20² + 2×a×110
0 = 400 + 220a
-400= 220a
a = - 400 / 220
a = - 1.818
a = - 1.82 m/s²
- stands for negative acceleration (deceleration)
