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
deff fn [24]
3 years ago
12

7. Two children of mass 20 kg and 30 kg sit balanced on a seesaw with the pivot point located at the center of the seesaw. If th

e children are separated by a distance of 3 m, at what distance from the pivot point is the small child sitting in order to maintain the balance?
Physics
1 answer:
Ainat [17]3 years ago
7 0

Answer:

Explanation:

Given

mass of children m_1=20\ kg

m_2=30\ kg

distance between two children L=3\ m

suppose  small child is at a distance of x m from  pivot point

so torque of small child and heavier child must be equal

20\times (x)=30\times (3-x)

2x=9-3x

5x=9

x=1.8\ m    

You might be interested in
An eagle flying at 35 m/s emits a cry whose frequency is 440 Hz. A blackbird is moving in the same direction as the eagle at 10
Akimi4 [234]

Answer:

a)  F=475.7Hz

b)  F'=410.899Hz

Explanation:

From the question we are told that:

Velocity of eagle V_1=35m/s

Frequency of eagle F_1=440Hz

Velocity of Black bird V_2=10m/s

Speed of sound s=343m/s

a)

Generally the equation for Frequency is mathematically given by

 F=f_0(\frac{v-v_2}{v-v_1})

 F=440(\frac{343-10}{343-35})

 F=475.7Hz

b)

Generally the equation for Frequency is mathematically given by

 F'=f_0(\frac{v+v_2}{v+v_1})

 F'=440(\frac{343+10}{343+35})

 F'=410.899Hz

7 0
3 years ago
Is baking a cake conduction, convection, or radiation?
Stolb23 [73]

Answer:

baking- is a method of cooking food that uses prolonged dry heat, normally in an oven, but also in hot ashes, or on hot stones. The primary source of heat is radiation. Fans within the oven will increase cooking times via convection of the air.

5 0
2 years ago
If a ball is given an initial speed of 15 m/s on a horizontal, frictionless surface, how fast will the ball be rolling in 5 seco
iris [78.8K]
The surface is frictionless, so there is no frictional force acting on the ball. There are no other forces acting on the ball in the horizontal direction, so it's a uniform motion with constant speed. Therefore, the velocity of the ball will remain the same for the entire duration of the motion, and so after 5 seconds the velocity is still 15 m/s.
7 0
3 years ago
An 800-g block of ice at 0.00°C is resting in a large bath of water at 0.00°C insulated from the environment. After an entropy c
Allisa [31]

Answer:

Unmeltedd ice = 308.109 g

Explanation:

Gibbs Free energy:

A systems Gibbs Free Energy is defined as the free energy of the product of the absolute temperature and the entropy change less than the enthalpy change.

Therefore, G = ΔH-TΔS

where G is Gibbs Free Energy

          ΔH is enthalpy change

          T is absolute temperature

          ΔS is entropy change

Here since there is a phase change, therefore G will be 0.

∴ΔH = TΔS

Given: Temperature, T = 0°C = 273 K

           Entropy change,ΔS = 600 J/K

           Latent heat of fusion of water = 333 J/g

∴ΔH = TΔS

  ∴ΔH = 273 x 600

           = 163800 J

So this is the amount of enthalpy that will be used into melting of ice.

  ∴ΔH = mass of ice melted x latent heat of fusion of water

    Mass of ice melted = ΔH / latent heat of fusion of water

                                     = 163800 / 333

                                     = 491.891 g

This is the mass of ice melted.

And initial amount of ice is 800 g

Amount of ice left after melting = Initial amount of ice - amount of ice melted

                                                   = 800-491.891

                                                  = 308.109 g

Amount of ice remained after melting = 308.109 g

8 0
3 years ago
A particle leaves the origin with an initial velocity v → = (3.00iˆ) m/s and a constant acceleration a → = (−1.00iˆ − 0.500jˆ) m
tatiyna

Answer:

the position vector (x,y) will be (1.5 m,-2.25 m) and the velocity vector (vx,vy) will be ( 0 m/s , -1.5 m/s) when x reaches its maximum x coordinate

Explanation:

Since the velocity is related with the acceleration and coordinates through

vx²=v₀x²+2*ax*x

where

vx = velocity in the x direction

v₀x = initial velocity in the x direction = 3 m/s

ax = acceleration in the x direction = −1.00 m/s²

x= coordinates in the x-axis

when x reaches its maximum coordinate , then vx=0

thus

vx²=v₀x²+2*ax*x

0 = (3 m/s)² + 2* (−1.00 m/s²)*x

x= 1.5 m

also for the time t

vx = v₀x + ax*t → t= (vx-v₀x)/ax = (0- 3 m/s)/  (−1.00 m/s²) = 3 seconds

for the y coordinates

y = y₀+v₀y*t + 1/2 ay*t²

where

v₀y = initial velocity in the y direction = 0 m/s

ay = acceleration in the x direction = −0.5 m/s²

y= coordinates in the y-axis

y₀= initial coordinate in the y-axis =0

then since y₀=0 and v₀y=0

y = 1/2*ay*t²

y = 1/2*ay*t² = 1/2*(−0.5 m/s²)*(3 s)² = -2.25 m

and

vy=v₀y+ ay*t= 0+(−0.5 m/s²)*(3 s)= (-1.5 m/s)

therefore the position vector (x,y) will be (1.5 m,-2.25 m)

and the velocity vector (vx,vy) will be ( 0 m/s , -1.5 m/s)

7 0
2 years ago
Other questions:
  • How is science controlled by the government?
    7·1 answer
  • Has scientific knowledge changed over time?
    8·1 answer
  • A wire is formed into a circle having a diameter of 10.3 cm and is placed in a uniform magnetic field of 2.98 mT. The wire carri
    13·1 answer
  • A 220 kg crate hangs from the end of a rope of length L = 14.0 m. You push horizontally on the crate with a varying force F to m
    6·1 answer
  • On a hot summer day, you need to leave your house for 30 minutes. To use the least amount of energy, should you turn off your ai
    8·1 answer
  • If the average mass of an adult is 86kg. Determine the mass and weight of an 86kg man in the moon where gravitational field is o
    12·1 answer
  • What is the final velocity of a 10 kg object that drops from rest and falls for 30 seconds?
    13·1 answer
  • In 3.0 seconds, a wave generator produces 15 pulses that spread over a distance of 45 centimeters. Calculate the wave's frequenc
    8·1 answer
  • In water, acids form _____.
    15·2 answers
  • NEED HELP!!!! 15 POINTS!!!!!!!
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!