The component of the crate's weight that is parallel to the ramp is the only force that acts in the direction of the crate's displacement. This component has a magnitude of
<em>F</em> = <em>mg</em> sin(20.0°) = (15.0 kg) (9.81 m/s^2) sin(20.0°) ≈ 50.3 N
Then the work done by this force on the crate as it slides down the ramp is
<em>W</em> = <em>F d</em> = (50.3 N) (2.0 m) ≈ 101 J
The work-energy theorem says that the total work done on the crate is equal to the change in its kinetic energy. Since it starts at rest, its initial kinetic energy is 0, so
<em>W</em> = <em>K</em> = 1/2 <em>mv</em> ^2
Solve for <em>v</em> :
<em>v</em> = √(2<em>W</em>/<em>m</em>) = √(2 (101 J) / (2.0 m)) ≈ 10.0 m/s
a. 0.5 T
- The amplitude A of a simple harmonic motion is the maximum displacement of the system with respect to the equilibrium position
- The period T is the time the system takes to complete one oscillation
During a full time period T, the mass on the spring oscillates back and forth, returning to its original position. This means that the total distance covered by the mass during a period T is 4 times the amplitude (4A), because the amplitude is just half the distance between the maximum and the minimum position, and during a time period the mass goes from the maximum to the minimum, and then back to the maximum.
So, the time t that the mass takes to move through a distance of 2 A can be found by using the proportion

and solving for t we find

b. 1.25T
Now we want to know the time t that the mass takes to move through a total distance of 5 A. SInce we know that
- the mass takes a time of 1 T to cover a distance of 4A
we can set the following proportion:

And by solving for t, we find

Hi there!
First, let's find the period of the pendulum. This can be found by solving for the amount of time it takes for the pendulum to make ONE complete swing.

Now, let's use the equation for the period of a simple pendulum:

T = Period (1.318 s)
L = length of string (0.55 m)
g = acceleration due to gravity on planet (? m/s²)
Let's solve for 'g' doing some quick rearranging of the equation:

Solving for 'g' by plugging in values:

Answer:
a) W₁ = 54000 Lb-ft
b) W₂ = 77760 Lb-ft
c) W₃ = 24000 Lb-ft
W₄ = 40560 Lb-ft
Step by step
W= ∫₁² ydF 1 and 2 are the levels of liquid
Where dF is the differential of weight of a thin layer
y is the height of the differential layer and
ρ*V = F
Then
dF = ρ* A*dy*g
ρ*g = 60 lb/ft³
A= Area of the base then
Area of the base is:
A(b) = 4*2 = 8 ft²
Now we have the liquid weighs 60 lb/ft³
Then the work is:
a)
W₁ = ∫₀¹⁵ 8*60*y*dy ⇒ W₁ =480* ∫₀¹⁵ y*dy
W₁ =480* y² /2 |₀¹⁵ ⇒ 480/2 [ (15)² - 0 ]
W₁ = 240*225
W₁ = 54000 Lb-ft
b) The same expression, but in this case we have to pump 3 feet higher, then:
W₂ = ∫₀¹⁸ 480*y*dy ⇒ 480*∫₀¹⁸ydy ⇒ 480* y²/2 |₀¹⁸
W₂ = 480/2 * (18)²
W₂ = 240*324
W₂ = 77760 Lb-ft
c) To pump two-thirds f the liquid we have
2/3* 15 = 10
W₃ = 480*∫₀¹⁰ y*dy ⇒ W₃ = 480* y²/2 |₀¹⁰
W₃ = 240*(10)²
W₃ = 24000 Lb-ft
d)
W₄ =480*∫₀¹³ y*dy
W₄ =480* y²/2 |₀¹³
W₄ = 240*(13)²
W₄ = 240*169
W₄ = 40560 Lb-ft