I don't know how to solve

A uniform cylinder of radius 25 cm and mass 27 kg is mounted so as to rotate freely about a horizontal axis that is parallel to

Alisiya [41]

Answer:

Explanation:

STEP 1

Given

Radius of cylinder = r = 25cm, 2.5m

mass = 27kg

cylinder is mounted so as to rotate freely about a horizontal axis that is parallel to and 60cm to the central logitudinal axis of the cylinder

height = 0.6m

part 1

The cylinder is mounted so as to rotate freely about a horizontal axis tha is paralle to 60cm from the central longitudinal axis of then cylinder. The rotational inertia of the cylinder about the axis of rotation is given by

I = Icm + mh²

∴ I = 1/2mr² + mh² = 1/2x27x (0.5)² + 20 x (0.6)²

I=13.09kg.m²

where

Icm is the rotational inertia of the cylinder about its central axis

m is the mass of the cylinder

h is the distance between the axis of the rotation and the central axis of the cylinder

r is the radius of the cylinder

 I=13.09kg.m²

part2

from the conservation of the total mechanical energy of the meter stick, the change in gravitational potential energyof the meter stick plus the change in kinetic energy must be zero

Δk + Δu = 0

1/2 I(w²-w²) = Ui-Uf

1/2 x 13.09w² = mgh

∴w=√20 x 9.8 x 0.6/(1/2 x 13.09) =117.6/6.5

w=18.09rad/s

5 0

4 years ago

In May 1990 the French TGV train traveled the distance from Paris to Lille, France (127 miles) in 0.819 hours. What was the spee

Degger [83]

Answer:

v=69.32 m/s

Explanation:

you have to transfer the distance from mile to meters (from miles to meters multiply by 1609)

so d=204387 m

you have to transfer the time from hour to second (from hour to second multiply by 3600)

so t=2948.4 s

the rule says v=d/t=204387/2948.4= 69.32 m/s

4 0

3 years ago

A 30 N rock falls from a 40 m cliff. At what point during its fall are its

vaieri [72.5K]

Answer:

Both energies are equal when the rock has fallen 20 m or equivalently when it is at a height of 20 m.

Explanation:

Potential and Kinetic Energy

The gravitational potential energy is the energy an object has due to its height above the ground. The formula is

$U=mgh$

Where:

m = mass of the object

g = acceleration of gravity (9.8~m/s^2)

h = height

Note we can also use the object's weight W=mg into the formula:

$U=Wh$

The kinetic energy is the energy an object has due to its speed:

$\displaystyle K=\frac{1}{2}mv^2$

Where v is the object's speed.

Initially, the object has no kinetic energy because it's assumed at rest.

The W=30 N rock falls from a height of h=40 m, thus:

$U=30*40=1,200 J$

Since the sum of the kinetic and potential energies is constant:

U' + K' = 1,200 J

Here, U' and K' are the energies at any point of the motion. Since both must be the same:

U' = K' = 600 J

U'=Wh'=600

Solving for h':

$\displaystyle h'=\frac{600}{W}=\frac{600}{30}=20~m$

Both energies are equal when the rock has fallen 20 m or equivalently when it is at a height of 20 m.

3 0

3 years ago

An arrow of 43 g moving at 84 m/s to the right, strikes an apple at rest. The arrow sticks to the apple and both travel at 16.8

Aloiza [94]

Answer:

The mass of the apple is 0.172 kg (172 g)

Explanation:

The Law Of Conservation Of Linear Momentum

The total momentum of a system of bodies is conserved unless an external force is applied to it. The formula for the momentum of a body with mass m and speed v is

P=mv.

If we have a system of two bodies, then the total momentum is the sum of both momentums:

$P=m_1v_1+m_2v_2$

If a collision occurs and the velocities change to v', the final momentum is:

$P'=m_1v'_1+m_2v'_2$

Since the total momentum is conserved, then:

P = P'

Or, equivalently:

$m_1v_1+m_2v_2=m_1v'_1+m_2v'_2$

If both masses stick together after the collision at a common speed v', then:

$m_1v_1+m_2v_2=(m_1+m_2)v'$

We are given the mass of an arrow m1=43 g = 0.043 kg traveling at v1=84 m/s to the right (positive direction). It strikes an apple of unknown mass m2 originally at rest (v2=0). The common speed after they collide is v'=16.8 m/s.

We need to solve the last equation for m2:

$m_2v_2-m_2v'=m_1v'-m_1v_1$

Factoring m2 and m1:

$m_2(v_2-v')=m_1(v'-v_1)$

Solving:

$\displaystyle m_2=\frac{m_1(v'-v_1)}{v_2-v'}$

Substituting:

$\displaystyle m_2=\frac{0.043(16.8-84)}{0-16.8}$

$\displaystyle m_2=\frac{-2.8896}{-16.8}$

$\displaystyle m_2=0.172\ kg$

The mass of the apple is 0.172 kg (172 g)

3 0

3 years ago

Intersystem crossing is:

Semenov [28]

An intersystem crossing (ISC) is a non-radiative process that involves the transition between two electronic states with different spin multiplicity. That is, when an electron is excited in a molecule in a basal singlet state (either by absorption or radiation) into a state of greater energy, an excited singlet or triplet state can be obtained.

Therefore, ISC is understood as an a non radio active transition between states with different spin multiplicity.

Correct answer is C: a radiative transition between states with the same spin.

8 0

4 years ago