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
Bad White [126]
3 years ago
14

A wooden rod of negligible mass and length 84.0 cm is pivoted about a horizontal axis through its center. A white rat with mass

0.600 kg clings to one end of the stick, and a mouse with mass 0.200 kg clings to the other end. The system is released from rest with the rod horizontal. If the animals can manage to hold on, what are their speeds as the rod swings through a vertical position?
Physics
1 answer:
Mandarinka [93]3 years ago
5 0

Answer:

v = 2.029 m/s

Explanation:

Given

L = 84.0 cm   ⇒  R = 0.5*L = 0.5*84 cm = 42 cm = 0.42 m

m₁ = 0.600 kg

m₂ = 0.200 kg

g = 9.8 m/s²

u₁ = u₂ = 0 m/s

v₁ = ?

v₂ = ?

Due to gravity, the bar oscillates and becomes vertical. The mass that occupies the lower position is the one with the highest torque. The one that reduces the potential energy (the system tends to the position of minimum energy). This is achieved if the mass that goes down is 0.6kg (that goes down 42cm) and the one that goes up is 0.2kg (goes up 42cm).

In this system mechanical energy is conserved, so we can match its value in the horizontal position with the one in the vertical.

then

Ei = Ki + Ui = 0.5*(m₁+m₂)*(0)² + (m₁+m₂)*9.8*(0) = 0 J

Ef = Kf + Uf

⇒ Kf = 0.5*(m₁+m₂)*v² = 0.5*(0.6+0.2)*v² = 0.4*v²

⇒ Uf = m₁*g*h₁ + m₂*g*h₂ = 0.6*9.8*(-0.42) + 0.2*9.8*0.42 = - 1.6464

⇒ Ef = Kf + Uf = 0.4*v² - 1.6464

Since

0 = 0.4*v² - 1.6464  ⇒  v = 2.029 m/s

v is the same value due to the wooden rod is pivoted about a horizontal axis through its center and the masses are on opposite ends.

v₁ = v₂ = v    ⇒  ω₁*R₁ = ω₂*R₂  ⇒ ω₁*R = ω₂*R  ⇒ ω₁ = ω₂ = ω

⇒ v = ω*R

You might be interested in
Choose all facts that increase the orbital velocity of a vessel around planet B. Bigger mass of planet B smaller mass of planet
telo118 [61]

Answer:

- Bigger mass of planet B  

- orbiting closer to planet B

Explanation:

The orbital velocity of the vessel around the planet can be found by equalizing the force of gravity between the vessel and the planet and the centripetal force:

G\frac{mM}{r^2}=m\frac{v^2}{r}

where

G is the gravitational constant

m is the mass of the vessel

M is the mass of the planet

r is the distance between the vessel and the centre of the planet

v is the orbital velocity of the vessel

Re-arranging the formula, we find an expression for v:

v=\sqrt{\frac{GM}{r}}

We see that:

- the bigger the mass of the planet, M, the bigger the velocity

- the bigger the distance between the vessel and the planet, r, the smaller the velocity

So, the correct choices that increase the orbital velocity are:

- Bigger mass of planet B  

- orbiting closer to planet B

6 0
3 years ago
Match each statement with the characteristic of scientists.
Dimas [21]

Answer:

Options B, A, D, C

Explanation:

When a scientists, let's say Roberto wonders if the presence of other elements also affects the color of a flame, he can decide to prove this through a study. Therefore, in chemistry class, Roberto sees that traces of lithium makes a flame appear bright red. Subsequently, Roberto designs an experiment to test flame color in the presence of different elements and finally Roberto's friend tells him the color of a flame cannot be changed, but Roberto is still unsure.

5 0
3 years ago
Read 2 more answers
The coefficient of performance of a residential heat pump is 1.6. Calculate the heating effect in kJ/s this heat pump will produ
grin007 [14]

Answer:

8 KJ/ s

Explanation:

Heat pumps Transfer thermal energy through absorbing of heat that comes from cold region and then release to warmer area by utilizing external power.

The coefficient of performance known as COP provide the ratio of both heating and cooling that are supplied to required work.

✓QH=The rate at which heat is produced = ?

✓COP= Coefficient of performance of a residential heat pump = 1.6

✓ W(in)= power consumption= 5KW

QH=The rate at which heat is produced=[Coefficient of performance of a residential heat pump] × [power consumption]

= 1.6 × 5KW

=8 KJ/ s

7 0
3 years ago
When looking through a fish tank, the mediums which light passes through are:
Alinara [238K]

The answer is : C ) air,water,and the tank glass.
-Hope this helps.

3 0
3 years ago
Read 2 more answers
What are the units of measure for distance?
olga2289 [7]
The most common unit is meters (m for short). It is the base unit for distance or displacement in the metric system. If you are dealing with larger distances, you might use kilometers (I'm for short) which is just 1000 meters. On the other hand, centimeter (cm) are used for small distances and are 1/100 of a meter. Another common unit is millimeters (mm) which is 1/1000 of a meter.
6 0
3 years ago
Other questions:
  • Answer for brainliest and mad points pllllssssssss
    7·1 answer
  • The unit of length most suitable for measuring the thickness of a cell phone is a
    7·1 answer
  • A 225 kg block is pulled by two horizontal forces. The first force is 178 N at a 41.7-degree angle and the second is 259 N at a
    12·1 answer
  • What is the first semiconductor
    15·1 answer
  • A string is wrapped several times around the rim of a small hoop with radius 7cm and mass 2kg. The free end of the string is hel
    8·1 answer
  • A 40 kg box has a surface area of 0.2 m2, determine its pressure.
    6·1 answer
  • A 15.0 m long plane is inclined at 30.0 degrees. If the coefficient of friction is 0.426, what force is required to move a 40.0
    13·1 answer
  • Which of these is true of all simple machines?
    15·1 answer
  • An empty container has a mass of 3 g. When it is filled with 5 cm3 of a liquid,
    9·1 answer
  • Proper use of the friction zone makes it easier to:.
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!