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
schepotkina [342]
3 years ago
7

An object of mass 100 kg is released from rest from a boat into the water and allowed to sink. While gravity is pulling the obje

ct​ down, a buoyancy force of StartFraction 1 Over 50 EndFraction times the weight of the object is pushing the object up​ (weight =​ mg). If we assume that water resistance exerts a force on the object that is proportional to the velocity of the​ object, with proportionality constant 10 ​N-sec/m, find the equation of motion of the object. After how many seconds will the velocity of the object be 90 ​m/sec? Assume that the acceleration due to gravity is 9.81 m divided by sec squared.
Mathematics
1 answer:
FrozenT [24]3 years ago
6 0

Answer:

a)  v_f = 9.6138*t / ( 1 + 0.1*t)

b) t = 147 s

Step-by-step explanation:

Given:

- The mass of the object m = 100 kg

- The buoyancy force F_b = W / 50

- The weight of the object = W = m*g

- Water resistance F_w = k*v

- Where, k = 10 Ns/m

Find:

a) find the equation of motion of the object.

b) After how many seconds will the velocity of the object be 90 ​m/sec?

Solution:

- Construct a FBD of the object, three forces acting on the object. Weight downwards, Buoyancy and drag force upwards. Use Newton's Second law of motion to evaluate the acceleration a.

                                     F_net = m*a

                                W - W/50 - 10*v = m*a

                                 a = 49/50*g - 10/m *v

Plug in the values:

                                 a = 49/50 * 9.81 - 10/100 * v

                                 a = 9.6138 - 0.1*v

- Using the first kinematic equation of motion we have:

                                 v_f = v_i + a*t

object was dropped from rest, v_i = 0, Hence:

                                 v_f = (9.6138 -0.1*v)*t  

                                v_f = 9.6138*t / ( 1 + 0.1*t)

Find the time t when v_f = 90 m/s

                                 90(1 + 0.1*t) = 9.6138*t

                                  90 + 9*t = 9.6138*t

                                  t = 90 / 0.6138 = 147 s

You might be interested in
How many possible weight's are there between 10 and 40 pounds
Kazeer [188]
The answer would be “D”.
8 0
3 years ago
Read 2 more answers
The product of a rational and irrational number is rational. always sometimes never
V125BC [204]

Answer:

"The product of a rational number and an irrational number is SOMETIMES irrational." If you multiply any irrational number by the rational number zero, the result will be zero, which is rational. Any other situation, however, of a rational times an irrational will be irrational.

Step-by-step explanation:

PLZ MARK BRAINLIEST

3 0
3 years ago
La desigualdad para comparar los numeros 11 y ‐9​
BaLLatris [955]

Answer:

dont speek that language

Step-by-step explanation:

8 0
3 years ago
Math problem I need help with
Kruka [31]

Answer:

31° is the answer thank you

7 0
2 years ago
Read 2 more answers
What is the temperature in degrees Fahrenheit of a freezer kept at-20 C.? NEED EQUATION EQUATION EQUATION.plz
LenKa [72]
So you would have -20C. Then you would multiply that by 1.8 which would give you -36 then you would add 32 which gives you your final answer which is -4 F
8 0
3 years ago
Other questions:
  • What is the solution to the system of equations below? y = negative three-fourths x + 3 and y = –12
    10·2 answers
  • A coin is loaded so that the probability of getting heads is 3/4. If the coin is flipped twice, what is the probability of getti
    7·1 answer
  • URGENT!!! <br> Can someone please answer these 2 questions and show the working out?
    8·1 answer
  • Answers? <br> domain and range of graphs
    6·1 answer
  • A young sumo wrestler decided to go on a special high-protein diet to gain weight rapidly. He started at 90 9090 kilograms and g
    12·1 answer
  • Please help! Correct answer only!
    15·1 answer
  • I will give you BRAINLIEST for the correct answer
    9·1 answer
  • I don't what to do<br> Only 1-9
    13·1 answer
  • Approximately how much fuel can fit into a tanker truck with a radius of 4 feet and a height of 32 feet?
    12·1 answer
  • 11 + 4n - 2n + 12 HELPPPPPPPPPPPPPPP
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!