For Anya:v 1 = 3.3 mph, v 2 = 8.3 mph5 : 2 = 2.5 mi ( half of the distance )
t1= d/v1 = 2.5 mi/ 3.3 mph = 0.7576 ht2 = d/v2 = 2.5 mi/8.3 mph = 0.3 hIn total: 0.7576 + 0.3 = 1.0576 hFor Ilya: 8.3 t / 2 + 3.3 t / 2 = 5 / * 28.3 t + 3.3 t = 1011.6 t = 10t = 10 : 11.6t = 0.86 hHe covers the distance for 0.86 h.His average speed:v = 5/0.86 = 5.81 mph.
Answer:
C. The sum remains the same.
Explanation:
The sum of the kinetic and potential energy remains the same as the all rolls from point A to E.
We know this based on the law of conservation of energy that is in play within the system.
The law of conservation of energy states that "energy is neither created nor destroyed within a system but transformed from one form to another".
- At the top of the potential energy is maximum
- As the ball rolls down, the potential energy is converted to kinetic energy.
- Potential energy is due to the position of a body
- Kinetic energy is due to the the motion of the body
In position #1, at time t₁ = 0, the coordinates are (1.1 m, 3.4 m).
That is,
x₁ = 1.1 m, y₁ = 3.4 m.
In position #2, at time t₂ = 3.0 s, the coordinates are (5.3 m, -0.5 m).
That is,
x₂ = 5.3 m, y₂ = -0.5 m.
The x-component of the average velocity is
Vx = (x₂ - x₁)/(t₂ - t₁)
= (5.3 - 1.1 m)/(3 - 0 s)
= 1.4 m/s
Similarly, the y-component of the average velocity is
Vy = (-0.5 - 3.4)/3
= -1.3 m/s
Answer
The x and y components of the average velocity are 1.4 m/s and -1.3 m/s respectively.