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
galina1969 [7]
3 years ago
12

A 12,000-kg lunar landing craft is about to touch down on the surface of the moon, where the acceleration due to gravity is 1.6

m/s2. At an altitude of 158 m the craft's downward velocity is 16.9 m/s. To slow down the craft, a retrorocket is firing to provide an upward thrust. Assuming the descent is vertical, find the magnitude of the thrust needed to reduce the velocity to zero at the instant when the craft touches the lunar surface. In newtons.
Physics
1 answer:
grin007 [14]3 years ago
6 0

Answer:

F = 8354.05 N

Explanation:

m = 12000 Kg

g = 1.6 m/s²

y = 158 m

vi = 16.9 m/s

vf = 0 m/s

F = ?

We can apply the following equation

F – W = - m*a    ⇒    F = W - m*a     ⇒   F = m*g - m*a = m*(g-a)     (I)

As a is an unknown magnitude, we can use the formula

vf² = vi² – 2*a*y  ⇒   0 = vi² – 2*a*y   ⇒   a = (vi²) / (2*y)

then  

a = (16.9 m/s)² / (2*158 m) = 0.9038 m/s²

Now we use the equation I

F = (12000 Kg)* (1.6 m/s² - 0.9038 m/s²) = 8354.05 N

You might be interested in
When energy is added to a wave, how can the wave change?.
nadya68 [22]

Answer:

When waves overlap in-phase (crest meets crest or trough meets trough) the waves energy is additive and the amplitude increases.

Explanation:

When waves overlap out-of-phase (crest meets trough) the waves cancel and the amplitude (energy) decreases. When two interfering waves cancel each other out.

6 0
2 years ago
A student places two books on a table. One book weighs less than the other book
Gnoma [55]
The book that weighs less
6 0
2 years ago
A swimming pool is 50 ft wide and 100 ft long and its bottom is an inclined plane, the shallow end having a depth of 4 ft and th
Nina [5.8K]

Explanation:

We define force as the product of mass and acceleration.

F = ma

It means that the object has zero net force when it is in rest state or it when it has no acceleration. However in the case of liquids. just like the above mentioned case, the water is at rest but it is still exerting a pressure on the walls of the swimming pool. That pressure exerted by the liquids in their rest state is known as hydro static force.

Given Data:

Width of the pool = w = 50 ft

length of the pool = l= 100 ft

Depth of the shallow end = h(s) = 4 ft

Depth of the deep end = h(d) = 10 ft.

weight density = ρg = 62.5 lb/ft

Solution:

a) Force on a shallow end:

F = \frac{pgwh}{2} (2x_{1}+h)

F = \frac{(62.5)(50)(4)}{2}(2(0)+4)

F = 25000 lb

b) Force on deep end:

F = \frac{pgwh}{2} (2x_{1}+h)

F = \frac{(62.5)(50)(10)}{2} (2(0)+10)

F = 187500 lb

c) Force on one of the sides:

As it is mentioned in the question that the bottom of the swimming pool is an inclined plane so sum of the forces on the rectangular part and triangular part will give us the force on one of the sides of the pool.

1) Force on the Rectangular part:

F = \frac{pg(l.h)}{2}(2(x_{1} )+ h)

x_{1} = 0\\h_{s} = 4ft

F = \frac{(62.5)(100)(2)}{2}(2(0)+4)

F =25000lb

2) Force on the triangular part:

F = \frac{pg(l.h)}{6} (3x_{1} +2h)

here

h = h(d) - h(s)

h = 10-4

h = 6ft

x_{1} = 4ft\\

F = \frac{62.5 (100)(6)}{6} (3(4)+2(6))

F = 150000 lb

now add both of these forces,

F = 25000lb + 150000lb

F = 175000lb

d) Force on the bottom:

F = \frac{pgw\sqrt{l^{2} + ((h_{d}) - h(s)) } (h_{d}+h_{s})   }{2}

F = \frac{62.5(50)\sqrt{100^{2}(10-4) } (10+4) }{2}

F = 2187937.5 lb

7 0
3 years ago
A mass of (200 g) of hot water at (75.0°C) is mixed with cold water of mass M at (5.0°C). The final temperature of the mixture i
SIZIF [17.4K]

The mass of the cold water, given the data from the question is 500 g

<h3>Data obtained from the question</h3>
  • Mass of warm water (Mᵥᵥ) = 200 g
  • Temperature warm water (Tᵥᵥ) = 75 °C
  • Temperature of cold water (T꜀) = 5 °C
  • Equilibrium temperature (Tₑ) = 25 °C
  • Specific heat capacity of the water = 4.184 J/gºC
  • Mass of cold water (M꜀) =?

<h3>How to determine the mass of the cold water </h3>

Heat loss = Heat gain

MᵥᵥC(Tᵥᵥ – Tₑ) = M꜀C(Tₑ – T꜀)

200 × 4.184 (75 – 25) = M꜀ × 4.184(25 – 5)

41840 = M꜀ × 83.68

Divide both side 83.68

M꜀ = 41840 / 83.68

M꜀ = 500 g

Learn more about heat transfer:

brainly.com/question/6363778

#SPJ1

4 0
2 years ago
A construction crew is paving a road. The crew has already paved 1,000 square feet and can pave at a rate of 300 square feet of
anyanavicka [17]

f(3) represents the number of additional square feet the construction crew has paved after 3 hours, not including the initial paved amount.

Mathematical models are representations of real situations. Models often serve the purpose of prediction and can help to explain and simplify certain mathematical problems.

The model; f(x) = 300x + 1,000 represents the number of additional square feet that can be paved in an hour after 1,000 square feet has already been paved.

From the above we can see that the correct answer is; "900 square feet; f(3) represents the number of additional square feet the construction crew has paved after 3 hours, not including the initial paved amount."

Learn more: brainly.com/question/731147

6 0
2 years ago
Other questions:
  • What are 3 subatomic particles of an atom?
    5·2 answers
  • How much power is expended if you lift a 60 n crate 10 meters in 1 second?
    6·1 answer
  • Friction changes the energy of an object from kinetic energy to _____________ energy?
    7·1 answer
  • What is the kinetic energy of a 620.0 kg roller coaster moving with a velocity of 9.00 m/s?
    14·2 answers
  • A 50 mm diameter steel shaft and a 100 mm long steel cylindrical bushing with an outer diameter of 70 mm have been incorrectly s
    7·1 answer
  • What is the frequency of a sound wave with a wavelength of 0.04 meter in air? What type of wave is
    15·2 answers
  • 24. Compare and contrast the 'Big Bang Theory' with the 'Creation Model for the origin of the
    14·1 answer
  • which of the following best represent positive self-talk A. "I'm making progress". B. "its just not my day". "I've tried. I just
    12·1 answer
  • Two mirrors are at right angles to one another. A light ray is incident on the first at an angle of 30° with respect to the norm
    6·1 answer
  • What can happen if water is removed from an aquifer faster than it can be replaced?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!