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A force of 1600 N acts parallel to a ramp to push a 300-kg piano into a moving van. The ramp is inclined at 20°.

(a) What is the acceleration of the piano up the ramp?
(b) What is the velocity of the piano when it reaches the top if the ramp is 4.0 m long and the piano starts from rest?

a) (a) 2.9 m/s², (b) 6.4 m/s
b) (a) 3.2 m/s², (b) 8.1 m/s
c) (a) 1.8 m/s², (b) 4.6 m/s
d) (a) 4.1 m/s², (b) 9.2 m/s

1 Answer

6 votes

Final answer:

According to the calculations based on Newton's second law and kinematic equations, the values obtained for the acceleration and velocity of the piano are 5.01 m/s² and 6.33 m/s, respectively. These results do not match the given answer choices, indicating a potential typo or error in the question's values or the provided answer options.

Step-by-step explanation:

To answer the student's question regarding the acceleration of the piano and its velocity at the top of the ramp, we can apply Newton's second law of motion and kinematic equations. Assuming no friction and air resistance, the force component parallel to the ramp used to accelerate the piano is cos(20°) * 1600 N

The parallel force is F = 1600 N * cos(20°) = 1503 N (rounded to three significant digits).

Using Newton's second law, acceleration is given by a = F/m, where F is the net force in the direction of motion, and m is the mass of the piano. So,

a = 1503 N / 300 kg = 5.01 m/s² (rounded to three significant digits).

However, this is not one of the available answer options provided by the student, meaning there was likely a typo or error in the question's given figures.

Given an acceleration and starting from rest, we can use the kinematic equation to find the velocity at the top of the ramp:

v² = u² + 2as, where u = initial velocity, a = acceleration, and s = distance.

v² = 0 + 2 * 5.01 m/s² * 4.0 m = 40.08 m²/s²

v = √40.08 m²/s² = 6.33 m/s (rounded to three significant digits).

Again, this calculation does not exactly match the provided answer choices, suggesting there may be an error in the given numerical values or the recognition of the choices. Therefore, we can't confidently decide which of the provided answer options (a, b, c, or d) is correct, as our calculations do not align with those values.

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