Answer:
d = 8 [m]
Explanation:
To solve this problem we must use the principle of conservation of energy, where the mechanical energy in a state plus the work done on the body, must be equal to the mechanical energy in the state Y. This can be easily represented in the following equation.
where:
Ex = Mechanical energy in X [J]
Wx-y = Work among states x and y [J]
Ey = Mechanical energy in Y [J].
The key to being able to understand this problem is that in state X, we only have kinetic energy, while the energy in state Y is equal to zero (there is no movement). The work is equal to the product of force by distance, as work acts in the opposite direction to movement, this has a negative sign.
![800 - F*d = 0\\100*d = 800\\d = 800/100\\d = 8 [m]](https://tex.z-dn.net/?f=800%20-%20F%2Ad%20%3D%200%5C%5C100%2Ad%20%3D%20800%5C%5Cd%20%3D%20800%2F100%5C%5Cd%20%3D%208%20%5Bm%5D)
Answer:
θ₁ = cos⁻¹ (n₁ / 2n₂)
Explanation:
For this exercise let's use the law of refraction
n₁ sint θ₁ = n₂. sin θ₂
Where n₁ and n₂ are the refractive indices for the two media, θ₁ and θ₂, the angles of incidence and refraction
They tell us that the angle of incidence is equal to the angle refracted over 2
θ₁ = θ₂ / 2
θ₂ = 2 θ₁
Let's replace
n₁ sin θ₁ = n₂ sin θ₂
Let's use the trigonometry relationship
sin 2θ = 2 sinθ cos θ
n₁ sin θ₁ = n₂ (2 sin θ₁ cos θ₁)
n₁ = n₂ cos θ₁
cos θ₁ = n₁ / 2 n₂
θ₁ = cos⁻¹ (n₁ / 2n₂)
Therefore, the angle of incidence is
θ₁ = cos⁻¹ (n₁ / 2n₂)
we know that
the speed is equal to
The slope of the line on the graph is equal to the speed of the car
so
during the segment B the slope of the line is equal to zero
that means
the speed of the car is zero
therefore
<u>the answer is the option B</u>
The car has come to a stop and has zero velocity
Answer:
v = 10.84 m/s
Explanation:
using the equation of motion:
v^2 = (v0)^2 + 2×a(r - r0)
<em>due to the hammer starting from rest, vo = 0 m/s and a = g , g is the gravitational acceleration.</em>
v^2 = 2×g(r - r0)
v = \sqrt{2×(-9.8)×(4 - 10)}
= 10.84 m/s
therefore, the velocity at r = 4 meters is 10.84 m/s
