An object having a mass of 2.0 kilograms falls from a height of 15 meters. What is its kinetic energy when it hits the ground?

Consider a double Atwood machine constructed as follows: A mass 4m is suspended from a string that passes over a massless pulley

kenny6666 [7]

Answer:

Hello your question is incomplete attached below is the complete question

Answer : x ( acceleration of mass 4m ) = $\frac{g}{7}$

The top pulley rotates because it has to keep the center of mass of the system at equilibrium

Explanation:

Given data:

mass suspended = 4 meters

mass suspended at other end = 3 meters

first we have to express the kinetic and potential energy equations

The general kinetic energy of the system can be written as

T = $\frac{4m}{2} x^2 + \frac{3m}{2} (-x+y)^2 + \frac{m}{2} (-x-y)^2$

T = $4mx^2 + 2my^2 -2mxy$

also the general potential energy can be expressed as

U = $-4mgx-3mg(-x+y)-mg(-x-y)+constant=-2mgy +constant$

The Lagrangian of the problem can now be setup as

$L =4mx^2 +2my^2 -2mxy +2mgy + constant$

next we will take the Euler-Lagrange equation for the generalized equations :

Euler-Lagrange equation = $4x-y =0\\-2y+x +g = 0$

solving the equations simultaneously

x ( acceleration of mass 4m ) = $\frac{g}{7}$

The top pulley rotates because it has to keep the center of mass of the system at equilibrium

8 0

2 years ago

A cart moves along a track at a velocity of 3.5 cm/s. when a force is applied to the cart, its velocity increases to 8.2 cm/s. i

oksian1 [2.3K]

Acceleration, in physics, is the rate of change of velocity of an object with respect to time. Anytime an object's velocity is changing, the object is said to be accelerating. It can be calculated as follows:

acceleration = 8.2 - 3.5 / 1.5 = 3.1 m/s²

Hope this answers the question.

5 0

2 years ago

Read 2 more answers

A simple generator has a square armature 6.0 cm on a side. The armature has 85 turns of 0.59-mm-diameter copper wire and rotates

FrozenT [24]

Answer:

f=15.5 Hz

Explanation:

Let's determine the internal resistance:

$R=\frac{(p*L)}{A}$

ρ = 1.68*10^-8 Ω m

$L=0.060m*4*60 = 14.4m$

$A=\pi*r^2\\A= \pi*(5.9x10^-4m/2)^2=2.734*10^-7m^2$

$R=(1.68*10^-8)*(14.4m)/(2.734*10^-7m^2)= 0.884$ Ω

Since the bulb is rated at 12.0 V and 25.0 W,

Current

$I=\frac{25W}{12.0v}=2.08 A$

Therefore, voltage drop inside generator =

$V=(2.08 A)*(0.88)=2.35v$

Actual EMF required is

$E_{mf}=12.0v+2.35v=14.35v$

Note that this is an RMS value.

The peak voltage is

$v_{peak}=14.15v*\sqrt{2} =20.29v$

For a generator, by Faraday's Law,

$E_{(max)}=N*B*A*w$

$20.29v=(60)*(0.650T)*(0.06m)^2$ *ω

ω $=144.5\frac{rad}{s}$

f=ω/(2π)=

f=144.5 rad/s/(2π)

f=23.001 Hz

6 0

2 years ago

Calculate the average velocity in m/y of a tectonic plate that has travelled 9000 km to the south in 60 million years

Gekata [30.6K]

The distance covered by the tectonic plate, in meters, is
 $d=9000km=9\cdot 10^6 m$ 
The time taken for the tectonic plate to cover this distance is equal to
 $t=60 mil.y=60 \cdot 10^6 y$ 
Therefore, the average velocity of the tectonic plate is the ratio between the distance covered and the time taken:
 $v= \frac{S}{t} = \frac{9\cdot 10^6m}{60 \cdot 10^6y} =0.15 m/y.$

8 0

2 years ago

Assume you are driving 20 mph on a straight road. Also, assume that at a speed of 20 miles per hour, it takes 100 feet to stop.

Viefleur [7K]

Answer:900 feet

Explanation:

Given

Velocity $\left ( V_1\right )=20 mph\approx 29.334 ft/s$