Average speed = total distance / time ⇒ total distance = average speed * time
Average speed = 270 km / p hours
distance = d
hours = x
d = 270/p * x
Answer:
The angle from the vertical is 48.72°
Explanation:
Given :
Length of rope m
Mass of man Kg
Mass of car Kg
Velocity of car
According to conservation law,
Potential energy of man is converted to kinetic energy of car moving,
We calculate height,
( ∵ )
m
This is the distance of the rope at the bottom,
So we take difference of it.
⇒
We can calculate angle between them,
48.72°
Therefore, the angle from the vertical is 48.72°
Choice c it's confusing to understand but it's c
Answer:
block K = 29.39 J and spring #1 Ke = 360 J
Explanation:
In this problem we have that the elastic energy of the spring becomes part kinetic energy and the part in work against the force of friction, so, to use the law of conservation of energy, the decrease in energy is the rubbing force work
= Ef - E₀
Let's look for the energies
Initial
E₀ = Ke = ½ k₁ x₁²
Final, this is just before starting to compress the spring
Ef = Ke = ½ m v²
The work of the rubbing force is
= -fr x
Let's write Newton's second law the y axis
N-W = 0
N = W
fr = μ N
fr = μ mg
Let's replace
-μ mg x = ½ m v² - ½ k₁ x₁²
v² = 2/m (½ k₁ x1₁² -μ mg x)
v² = 2/6 (½ 2000 0.6²2 - 0.5 6 9.8 1) = 1/3 (360 - 29.4)
v = 3.13 m / s
With this value we calculate the energy of the block
K = ½ m v²
K = ½ 6 3.13²
K = 29.39 J
Calculate eenrgy of the spring ke 1
Ke = ½ k₁ x₁²
Ke = ½ 2000 0.60²
Ke = 360 J