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
Zigmanuir [339]
4 years ago
6

A machine is rolling a metal cylinder under pressure. The radius of the cylinder is decreasing at a constant rate of 0.05 inches

per second and the volume, V, is 128pi cubic inches. At what rate is the length, h, changing when the radius, r, is 1.5 inches? Note: V=pi(r^2)h
Hi, as above this is the problem I am doing. There is no answer given to check so I was wondering about a couple of things:

Is volume assumed to be a constant in this problem?

Is the height change decreasing (negative rate) or increasing (positive rate) in the final answer?

I worked out dh/dt to be 512/135 in./s
Physics
1 answer:
Luden [163]4 years ago
4 0
Yes, the volume of the cylinder will remain constant. As the radius decreases, the height will increase to make sure that the volume is kept the same.
We have been given a value of dr/dt and are required to find dh/dt
Because the volume is constant, we can plug it into the formula for the volume of the cylinder and rearrange it to make h the subject:
128 = πr²h
h = 128/πr²
Now we differentiate both sides:
dh/dr = -256/πr³
Applying the chain rule:
dh/dt = dh/dr x dr/dt
dh/dt = (-256/πr³) x -0.05
dh/dt = 64/5πr³; substituting the value of r
dh/dt = 64/5π(1.5)³
dh/dt = 1.21 in/sec
You might be interested in
A uniform cubical crate is 0.740 m on each side and weighs 600 N. It rests on the floor with one edge against a very small, fixe
Sindrei [870]

Answer:

H = 0.673

Explanation:

given,

side of cubical crate = 0.74

weight of the crate = 600 N

magnitude of force = 330 N

the Horizontal distance of its Center of mass

= 0.74/2

= 0.37

Let the required Height be H

By Balancing the Torques, we get

H x 330 N = 0.37 x 600

330 H = 222

H = 0.673

hence, the height above the floor where force is acting is equal to 0.673 m

6 0
3 years ago
Use the worked example above to help you solve this problem. An Alaskan rescue plane drops a package of emergency rations to str
Vlad [161]

Answer:

(a) The package lands 682 meters horizontally ahead from the point the package was dropped from the plane

(b) The horizontal component = 39.0 m/s

The vertical component = 171.55 m/s

(c) The angle of impact is 77.19°

Explanation:

The parameters given are;

Velocity of the plane, vₓ = 39.0 m/s

Height of the plane above the ground, h = 1.50 × 10² m = 1,500 m

(a) The time, t, before the package hits the ground when dropped from the plane is given by the relation;

h = u·t + 1/2×g×t²

Where:

g = Acceleration due to gravity = 9.81 m/s²

u = Initial vertical velocity = 0 m/s

Hence;

1500 = 0×t + 1/2 × 9.81 × t² = 4.905·t²

∴ t = √(1500/4.905) = 17.49 s

The horizontal distance the package travels before landing = 17.49 × 39 ≈ 682 m

The package lands 682 meters horizontally ahead from the point the package was dropped from the plane

(b) The vertical velocity, v_y, of the package just before landing is given by the relation;

v_y² = u² + 2·g·h

u = 0 m/s

∴ v_y² = 0 + 2×9.81×1500 = 29430 m²/s²

v_y = √29430  = 171.55 m/s

Hence the horizontal component = 39.0 m/s

The vertical component = 171.55 m/s

(c) The angle of impact, θ, is given as follows;

tan \theta = \dfrac{v_y}{v_x}  = \dfrac{171.55}{39.0 } = 4.4

∴ θ = tan⁻¹(4.4) = 77.19°.

6 0
4 years ago
PLEASE HELP!!!!!!!! More science questions coming soon!!
Naily [24]

Answer:

1.) A - 1,2,1,2

2.) Both forces can act without objects touching.

3.) C

Both can be modeled as waves having amplitude, frequency and wave lengths.

4.) A, B and C

Explanation:

1.) SO2 + ___ H2 ----------> _____ S + _______H2O

Looking at above equation, we have one molecule of surfur at the right hand side (RHS), and one molecule of surfur at the left hand side (LHS).

Two atoms of hydrogen and both RHS and LHS

But oxygen is not balanced. We have two atoms of oxygen at the RHS while having one at the LHS.

So let's make oxygen 2 atoms at LHS by adding 2 to water molecules and hydrogen molecules at the RHS.

SO2 + ___ 2H2 ----------> _____ S + _______2H2O

The correct answer is A - 1,2,1,2

2.) Both magnetic force and gravitational force obey inverse square law with distance. They are not directly proportional but inversely proportional to the square distance. B is the correct answer because Both forces can act without objects touching.

3.) Light waves are transverse waves which can travel through a vacuum without a medium while sound waves are longitudinal waves which cannot travel through vacuum without a medium. But both can be modeled as waves having amplitude, frequency and wave lengths.

4.) If an object is slowing down, due to conservation of energy,

The potential energy could be increasing, like a ball thrown into the air.

The kinetic energy could be lost to friction or air resistance.

The ball could be returning to its natural resting state.

7 0
3 years ago
B. How can you tell where sugar enters the blood?
Korolek [52]

Answer:

Sugar can’t enter cells directly

Explanation:

So when blood sugar level rises, cells in the pancreas signal for the release of insulin into the bloodstream. The insulin attaches to the sugars and signals cells to let it enter with the attached sugar. Insulin is known as the key that unlocks cells.

I hope I helped

8 0
3 years ago
Pls help i will give u brianliest!
Fofino [41]

Answer:

Explanation:

neautrons and protons

3 0
3 years ago
Other questions:
  • The law of conservation of mass states that in a chemical reaction matter is not created or destroyed true or false
    5·1 answer
  • What does the term “periodic” mean when describing motion
    7·2 answers
  • Which trends is indirectly proportional to effective nuclear charge
    12·1 answer
  • How many electrons would it take to make up 1 C of charge? ( Coulomb’s law )
    12·1 answer
  • What is another name for Kepler's Third Law? Select all that apply.
    8·1 answer
  • For a point charge, how does the potential vary with distance from the point charge, r?
    8·1 answer
  • Explain why saucepans are much more common with plastic handles than metal handles.
    8·2 answers
  • Select the correct answer. Using the right hand rule, what do the three numbered vectors represent in the diagram below? A. 1) f
    11·2 answers
  • A child has a toy balloon with a volume of 1.80 L. The temperature of the balloon when it was filled was 20.ºC and the pressure
    11·1 answer
  • Calculate their densties in Si unit.<br>200mg,0.0004m​
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!