Ask question

Ask question

All categories

3 years ago

10

A coconut falls out of a tree 12.0 m above the ground and hits a bystander 3.00 m tall on the top of the head. It bounces back u

p 1.50 m before falling to the ground. If the mass of the coconut is
2.00 kg, calculate the potential energy of the coconut relative to the ground at each of the following sites:
(a) while it is still in the tree,
(b) when it hits the bystander on the head,
(c) when it bounces up to its maximum height,
(d) when it lands on the ground,
(e) when it rolls into a groundhog hole, and falls 2.50 m to the bottom of the hole.

1 answer:

quester [9]3 years ago

6 0

Answer:

A. 240 J

B. 60 J

C. 90 J

D. 0 J

E. 50 J

Explanation:

A. Determination of the potential energy of the coconut while it is still in the tree

Mass (m) = 2 Kg

Acceleration due to gravity (g) = 10 m/s²

Height (h) = 12 m

Potential energy (PE) =.?

PE = mgh

PE = 2 × 10 × 12

PE = 240 J

B. Determination of the potential energy of the coconut when it hits the bystander on the head,

Mass (m) = 2 Kg

Acceleration due to gravity (g) = 10 m/s²

Height (h) = 3 m

Potential energy (PE) =.?

PE = mgh

PE = 2 × 10 × 3

PE = 60 J

C. Determination of the potential energy of the coconut when it bounces up to its maximum height,

Mass (m) = 2 Kg

Acceleration due to gravity (g) = 10 m/s²

Height (h) = 3 + 1.5 = 4.5 m

Potential energy (PE) =.?

PE = mgh

PE = 2 × 10 × 4.5

PE = 90 J

D. Determination of the potential energy of the coconut when it lands on the ground,

Mass (m) = 2 Kg

Acceleration due to gravity (g) = 10 m/s²

Height (h) = 0 m

Potential energy (PE) =.?

PE = mgh

PE = 2 × 10 × 0

PE = 0 J

E. Determination of the potential energy of the coconut when it rolls into a ground hole, and falls 2.50 m to the bottom of the hole.

Mass (m) = 2 Kg

Acceleration due to gravity (g) = 10 m/s²

Height (h) = 2.50 m

Potential energy (PE) =.?

PE = mgh

PE = 2 × 10 × 2.50

PE = 50 J

You might be interested in

1. Consider three objects: Object A is a hoop of mass m and radius r; Object B is a sphere

Zarrin [17]

a) Object C (the disk) has the greatest rotational inertia ( $\frac{3}{2}mr^2$ )

b) Object B (the sphere) has the smallest rotational inertia ( $\frac{4}{5}mr^2$ )

Explanation:

The moments of inertia of the three objects are the following:

1) For a hoop of negligible thickness, it is

$I=MR^2$

where M is its mass and R its radius. For the hoop in this problem,

M = m

R = r

Therefore, its moment of inertia is

$I=(m)(r)^2=mr^2$

2) For a solid sphere, the moment of inertia is

$I=\frac{2}{5}MR^2$

where M is its mass and R its radius. For the sphere in this problem,

M = 2m

R = r

Therefore, its moment of inertia is

$I=\frac{2}{5}(2m)(r)^2=\frac{4}{5}mr^2$

3) For a disk of negligible thickness, the moment of inertia is

$I=\frac{1}{2}MR^2$

where M is its mass and R its radius. For the disk in this problem,

M = 3m

R = r

Therefore, its moment of inertia is

$I=\frac{1}{2}(3m)(r)^2=\frac{3}{2}mr^2$

So now we can answer the two questions:

a) Object C (the disk) has the greatest rotational inertia ( $\frac{3}{2}mr^2$ )

b) Object B (the sphere) has the smallest rotational inertia ( $\frac{4}{5}mr^2$ )

Learn more about inertia:

brainly.com/question/2286502

brainly.com/question/691705

#LearnwithBrainly

7 0

4 years ago

Nio conducts a science experiment. He puts yeast into a bottle with water and sugar, and then caps the bottle with a balloon. He

KATRIN_1 [288]

Answer: Option (C) is the correct answer.

Explanation:

When yeast is added into a bottle with water and sugar then after some time yeast becomes activated. This results in the formation of a chemical change as bubbles are formed on the surface of the mixture in the bottle.

This indicates that a gas has been released due to the chemical change.

Thus, we can conclude that most likely a chemical change has occurred because a gas was produced.

3 0

4 years ago

Read 2 more answers

How remove local action and polarization

slava [35]

Answer:

Local action is removed by amalgamating zinc rod.

Explanation:

This prevents chemical reaction to occur because impurities in the zinc cannot get into contact with an electrolyte.

8 0

4 years ago

A heat engine operating between energy reservoirs at 20?c and 600?c has 30% of the maximum possible efficiency.

Anarel [89]

<span>The maximum possible efficiency, i.e the efficiency of a Carnot engine , is give by the ratio of the absolute temperatures of hot and cold reservoir.
η_max = 1 - (T_c/T_h)

For this engine:
η_max = 1 - [ (20 +273)K/(600 + 273)K ] = 0.66 = 66%

The actual efficiency of the engine is 30%, i.e.
η = 0.3 ∙ 0.664 = 0.20 = 20 %

On the other hand thermal efficiency is defined as the ratio of work done to the amount of heat absorbed from hot reservoir:
η = W/Q_h

So the heat required from hot reservoir is:
Q_h = W/η = 1000J / 0.20 = 5000J</span>

8 0

3 years ago

An empty 2,500 kg train car is headed northbound at a velocity of 5 m/s. Ahead of the first car, an empty 1,500 kg car is headed

Tema [17]

Let the mass of 2500 kg car be $m_1$ and it's velocity be $v_1$ and the mass of 1500 kg car be $m_2$ and it's velocity be $v_2$ .

After the bumping the mass be M and it's velocity be V.

By law of conservation of momentum we have

$m_1v_1+m_2v_2 = MV$

2500 * 5 + 1500 * 1=4000 * V

V = 14000/4000 = 7/2 = 3.5 m/s

So the velocity of the two-car train = 3.5 m/s

9 0

3 years ago