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Kazeer
2 months ago
8

An object is released from rest near and above Earth’s surface from a distance of 10m. After applying the appropriate kinematic

equation, a student predicts that it will take 1.43s for the object to reach the ground with a speed of 14.3m/s . After performing the experiment, it is found that the object reaches the ground after a time of 3.2s. How should the student determine the actual speed of the object when it reaches the ground? Assume that the acceleration of the object is constant as it falls.
Physics
1 answer:
serg [3.5K]2 months ago
4 0

Answer:

v_y = 12.54 m/s

Explanation:

Given values:

- Initial vertical height y_o = 10 m

- Initial velocity v_y,o = 0 m/s

- The object's acceleration in the air = a_y

- The actual time taken to reach the ground t = 3.2 s

Find:

- How to calculate the object's speed when it arrives at the ground?

Solution:

- Apply kinematic equations to find the actual acceleration of the ball when it reaches the ground:

y = y_o + v_y,o*t + 0.5*a_y*t^2

0 = 10 + 0 + 0.5*a_y*(3.2)^2

a_y = - 20 / (3.2)^2 = 1.953125 m/s^2

- Use the total energy conservation principle of the system:

E_p - W_f = E_k

Where, E_p = m*g*y_o

W_f = m*a_y*(y_i - y_f)..... Reflecting air resistance

E_k = 0.5*m*v_y^2

Thus, m*g*y_o - m*a_y*(y_i - y_f) = 0.5*m*v_y^2

g*(10) - (1.953125)*(10) = 0.5*v_y^2

v_y = sqrt(157.1375)

v_y = 12.54 m/s

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Explanation:

Here is the data provided:

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v = \sqrt{\frac{3RT}{M} }............................1

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time taken = \frac{r}{v}

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3 0
1 month ago
Which of the following combinations of variables results in the greatest period for a pendulum? length = L, mass = M, and maximu
Yuliya22 [3333]

Response:

length = 2L, mass = M/2, and maximum angular displacement = 1 degree

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A hard rubber rod with an electric potential energy of 5.2 × 10–3 J has a charge of 4.0 µC at the tip. What is the electric pote
Keith_Richards [3271]
1) The electric potential energy can be defined as the product of the electric potential and the associated charge:
U=q V
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V= \frac{U}{q}= \frac{5.2 \cdot 10^{-3}J}{4.0 \cdot 10^{-6} C}=1300 V=1.3 \cdot 10^3 V

2) Using this same formula, if the charge changes to q=2.0 \mu C = 2.0 \cdot 10^{-6} C, the resulting electric potential will be:
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8 0
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23. While sliding a couch across a floor, Andrea and Jennifer exert forces F → A and F → J on the couch. Andrea’s force is due n
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Response:

a) (95.4 i^ + 282.6 j^) N, b) 298.27 N 71.3º and c) F' = 298.27 N θ = 251.4º

Justification:

a) Using trigonometric functions, we can resolve Jennifer's force

sin θ = Fjy / Fj

cos θ = Fjx / Fj

Calculating the angle, which is 32º to the east of north, taken from the positive x-axis:

T = 90 -32 = 58º

Fjy = Fj sin 58

Fjx = FJ cos 58

Fjx = 180 cos 58 = 95.4 N

Fjy = 180 sin 58 = 152.6 N

Andrea's exerted force is

Fa = 130.0 j ^

Summing forces across both axes:

X axis

Fx = Fjx

Fx = 95.4 N

Y axis

Fy = Fjy + Fa

Fy = 152.6 + 130

Fy = 282.6 N

F = (95.4 i ^ + 282.6 j ^) N

b) Now let's employ the Pythagorean theorem and trigonometry

F² = Fx² + Fy²

F = √ (95.4² + 282.6²)

F = √ (88963)

F = 298.27 N

tan θ = Fy / Fx

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θ = tan-1 (2.962)

θ = 71.3º

c) To counteract the motion, they must apply an opposing force of equal intensity:

F' = 298.27 N

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θ = 251.4º

4 0
1 month ago
How many top quark lifetimes have there been in the history of the universe (i.e., what is the age of the universe divided by th
inna [3103]

Answer:

times1.0\cdot 10^{41}

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Age of the universe:

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6 0
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