Answer:
a) y = 400 ft b) y = 350 ft
Explanation:
We can solve that problem with kinematic relationships
y = v₀ t + ½ a t²
Let's apply this equation to the elevator 1
y₁ = v₀ t₁ + ½ to t₁²
time t= 1 s
y₁ = v₀ 1 + ½ a 1²
y₁ = v₀ + ½ a
For t = 2s
y₂ = v₀ 2 + ½ a 2²
y₂ = 2 v₀ + 2 a
Let's write the equations and solve the system
4 = v₀ + ½ a
9 = 2 v₀ + 2 a
Let's multiply the first by -2
-8 = -2v₀ -a
9 = 2v₀ + 2 a
Let's add
1 = a
We replace in the first
4 = v₀ + ½ 1
v₀ = 4- 1/2
v₀ = 3.5
The equation for the first elevator is
y = 3.5 t + ½ t²
For t = 10 s
y = 3.5 10 + ½ 10²
y = 400 ft
We repeat the process for the second elevator
t = 1s
y₁ = v₀ 1 + ½ a 1²
3.5 = v₀ + ½ a
t = 2 s
y₂ = v₀ 2 + ½ a 2²
6.5 = 2 v₀ +2 a
multiply by -2
-7 = -2 v₀ - a
6.5 = 2 v₀ + 2 a
Let's add
-0.5 = a
I replace in the first equation
3.5 = v₀ + ½ (-0.5)
v₀ = 3.5 + 0.25
v₀ = 3.75
The equation is
y = 3.75 t -0.25 t²
For t = 10s
y = 3.75 10 - 0.25 10²
y = 350 ft
Night hunting animals have more rod cells in their retinas which allows them to see better in the dark.
The distance it falls is given by
x = (1/2)at^2
where a = acceleration due to gravity = 9.8 m/s^2
x = (1/2)(9.8)(18)^2
x = 1587.6 m
The answer is 1587.6 meters
Answer:
|F| = 393750 N
Explanation:
Given that,
Total mass of the train, m = 750000 kg
Initial speed, u = 84 m/s
Final speed, v = 42 m/s
Time, t = 80 s
We need to find the net force acting on the train. The formula for force is given by :
F = ma

So, the magnitude of net force is 393750 N.