1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Lesechka [4]
3 years ago
9

Three balls are thrown off the top of a building, all with the same speed but with different launch angles (position is given in

meters and time is given in seconds). The components of the initial velocities are given.
The blue ball has an initial velocity of (6 m/s, 8 m/s).
The green ball has an initial velocity of (10 m/s, 0 m/s).
The red ball has an initial velocity of (8 m/s, -6 m/s).

a. Rank the three balls according to which one hits the ground first.
b. Rank the three balls according to which one has the greatest speed the instant before impact with the ground.
c. Calculate the speed of each of the balls the instant before impact with the ground.
Physics
1 answer:
jek_recluse [69]3 years ago
4 0

Answer:

A. Red, Green, Blue

B. None. They all hit the ground with the same speed.

C. Final Kinetic Energy = Initial Gravitational Potential Energy

Explanation:

A. This one is actually just common sense. If you think about it, the object that is being thrown downward will reach the ground first. The object thrown upwards will hit the ground the last. If you don't believe me, use just the vertical component of velocity and use acceleration = 9.8 m/s^2. Find the time it takes for an arbitrary displacement each ball will travel. You will find that the one pointed downward will reach the ground in the shortest amount of time. Just do the same math over for the rest of the balls and you can find the time it takes for each ball to hit the ground.

B. This one is actually really simple if you think about it. Using the Work-Energy theorem, using the system consisting a ball and the earth there will be no external forces doing work on the system. Since each ball is at some height "h" and the same initial speed, they will all have the same amount of energy in the beginning. If we set the ground as our reference point for gravitational potential energy, then there will be no gravitational energy as the height at that point will be 0. They all must have the same kinetic energy at the ground.

C.

Mechanical Energy Final = Mechanical Energy Initial + Net Work from non-conservative forces

Kinetic Energy Final + Gravitational Potential Energy Final = Kinetic Energy Initial + Gravitational Potential Energy Initial

I am using the symbol " ' " to indicate final speeds and heights

0.5*m*v'^2 + mgh' = 0.5*m*v^2 + mgh

0.5*m*v'^2 + 0 = 0.5*m*v^2 + mgh

(cancel out the mass)

0.5*v'^2 = 0.5*v^2 +gh

Since the "v" is the same initially for all three balls and "g" and "h" are the same for all three balls. The final speed v' must be the same for all three situations regardless of mass.

If you have any questions feel free to comment again. I'll try to clarify.

You might be interested in
Someone please help me with finding the resistance of these circuits! I've been asking for an hour now. I will give brainliest i
vivado [14]

Answer:

1. 59 Ω

2. 3 Ω

3. 0.625 kΩ

Explanation:

1. The total resistance in a series circuit is equal to the sum of the resistance.

R_T=R_1+R_2+R_3...\\R_T=20+19+20\\R_T=59

Therefore, the total resistance in the first circuit is 59 Ω.

2. The total resistance in a parallel circuit is equal to the sum of the reciprocals of the resistance.

\frac{1}{R_T} = \frac{1}{R_1} +\frac{1}{R_2} +\frac{1}{R_3} ...\\\frac{1}{R_T} = \frac{1}{6.0} +\frac{1}{12} +\frac{1}{36}+\frac{1}{18} \\\frac{1}{R_T} = \frac{1}{3} \\R_T=3

Therefore, the total resistance in the second circuit is 3 Ω.

3. This is another parallel circuit, so we use the same equation from above:

\frac{1}{R_T} = \frac{1}{R_1} +\frac{1}{R_2} +\frac{1}{R_3} ...\\\frac{1}{R_T} = \frac{1}{10} +\frac{1}{2} +\frac{1}{1} ...\\\frac{1}{R_T} =1.6\\R_T=\frac{1}{1.6}

Therefore, the total resistance in the third circuit is \frac{1}{1.6} kΩ, or 0.625 kΩ.

I hope this helps!

8 0
3 years ago
Nvhfbvhefvhabjbnvjhhjaqiuv.....
Agata [3.3K]

Answer:

I don’t understand it

Explanation:

If anyone can the. Let me know

5 0
3 years ago
A 2.1 kg block is dropped from rest from a height of 5.5 m above the top of the spring. When the block is momentarily at rest, t
ella [17]

Answer:

The speed of the block is 8.2 m/s

Explanation:

Given;

mass of block, m = 2.1 kg

height above the top of the spring, h = 5.5 m

First, we determine the spring constant based on the principle of conservation of potential energy

¹/₂Kx² = mg(h +x)

¹/₂K(0.25)² = 2.1 x 9.8(5.5 +0.25)

0.03125K = 118.335

K = 118.335 / 0.03125

K = 3786.72 N/m

Total energy stored in the block at rest is only potential energy given as:

E = U = mgh

U = 2.1 x 9.8 x 5.5 = 113.19 J

Work done in compressing the spring to 15.0 cm:

W = ¹/₂Kx² = ¹/₂ (3786.72)(0.15)² = 42.6 J

This is equal to elastic potential energy stored in the spring,

Then, kinetic energy of the spring is given as:

K.E = E - W

K.E = 113.19 J - 42.6 J

K.E = 70.59 J

To determine the speed of the block due to this energy:

KE =  ¹/₂mv²

70.59 =  ¹/₂ x 2.1 x v²

70.59 = 1.05v²

v² = 70.59 / 1.05

v² = 67.229

v = √67.229

v = 8.2 m/s

8 0
3 years ago
Read 2 more answers
A ball of 12 kg is attached to a string of 0.8 meter spun at 4
lesantik [10]

Answer:

240 N

Explanation:

6 0
3 years ago
Which type of relationship is formed when a megabat eats a fig and drops the
Alina [70]

The type of relationship formed when a megabat eats a fig and drops the seeds in a new location is COMENSALISM. It is an ecological interaction.

<h3>What is commensalism?</h3>

Commensalism is a type of ecological interaction in which one organism benefits (in this case, the tree)  and the other organism neither benefits nor harm (the megabat).

Mutualism is a type of ecological association in which both organisms benefit from such interaction.

Conversely, parasitism is a type of ecological interaction in which one organism benefits and the other organism is harmed.

Learn more about commensalism here:

brainly.com/question/16712254

3 0
3 years ago
Other questions:
  • Which of the following happens during a lunar eclipse? The moon appears red. The moon casts a shadow on Earth. Earth, the moon a
    9·2 answers
  • ASAP!
    13·2 answers
  • What is atmospheric pressure and what are the diffetent units?
    15·1 answer
  • Farah claps his 600times in 60seconds. what is the friquency and periodb​
    11·1 answer
  • Monochromatic light is incident on a grating that is 75 mmwide
    8·1 answer
  • A condition that affects the ability to sleep or the quality of sleep is referred to as a __________.
    8·2 answers
  • 2. When pressing the accelerator on a
    6·1 answer
  • Using water displacement to find volume of an irregular object: A submerged object will displace a volume of water that is equal
    6·1 answer
  • What 3 things use electromagnetic energy in nature?​
    12·1 answer
  • The agonist in a movement is the muscle that provides the major force to complete the movement
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!