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
Softa [21]
3 years ago
7

Melissa uses bags of mulch that way 40 pounds each. She needs to carry 10 bags to her truck. She usually carries one bag at a ti

me. Would she do less work if she carried two bags at a time?
Physics
1 answer:
arsen [322]3 years ago
4 0
No. She would be doing the same amount of work that way. Work is defined to be equal to the force multiplied by the distance. Carrying two bags at a time would cause her to exert twice the effort, so the total amount of work done in the end would still be the same.
You might be interested in
A ball rolls downhill with a constant acceleration of 4m/s squared. If it started from rest,it’s velocity at the end of 3 meters
vladimir2022 [97]

Answer:

4.9 m/s

Explanation:

Since the motion of the ball is a uniformly accelerated motion (constant acceleration), we can solve the problem by using the following suvat equation:

v^2-u^2=2as

where

v is the final velocity

u is the initial velocity

a is the acceleration

s is the distance covered

For the ball in this problem,

u = 0 (it starts from rest)

a=4 m/s^2 is the acceleration

s = 3 m is the distance covered

Solving for v,

v=\sqrt{u^2+2as}=\sqrt{0+2(4)(3)}=4.9 m/s

3 0
3 years ago
True or false: When an object becomes polarized, it acquires a charge and becomes a charged object.​
PSYCHO15rus [73]

Answer:

i think its true

Explanation:

8 0
3 years ago
(LC)Light fixtures and placement that create shadows on the set, that obscure or completely hide action in certain areas of the
Sedaia [141]

The correct answer is true.

It is true that light fixtures and placement that create shadows on the set, that obscure or completely hide action in certain areas of the set, or that change as the main character’s emotional state changes are all ways that lighting can be used to heighten the drama and suspense in dramatic films.

Lighting plays an important role in film making because it can create scenes that enhance the de drama of the moment or the right mood that the director wants to share. Lighting in the film is an art because the basic principle is that the scene needs to look natural. From that principle, filmmakers and light specialist cand create many kinds of dramatic or jubilation moments if they know how to apply light principles to each scene.

5 0
3 years ago
One of the most efficient engines built so far has the following characteristics: combustion chamber temperature = 1900°C, exhau
suter [353]

Answer:

actual efficiency is  47.78 %

Carnot efficiency  is 67.65 %

power output is 5.20 × 10^3 hp

Explanation:

given data

temperature = 1900°C = 1900+ 273 K = 2173 K

exhaust temperature = 430°C = 430 + 273 K = 703 K

fuel = 7.0 × 10^9 cal

work = 1.4 × 10^10 J

to find out

actual efficiency  and Carnot efficiency and power output of engine

solution

first we find actual efficiency that is = work / heat input

put the value and

input energy  = 7.0 × 10^9 cal  (4.184 J/1 cal)  = 29.29 × 10^9 J

actual efficiency  =  1.4 × 10^10 / ( 29.29 × 10^9 )

actual efficiency  =  0.4778

actual efficiency is  47.78 %

and

Carnot efficiency  is = 1 - ( 703 / 2173 )

so Carnot efficiency  is  = 0.67648

Carnot efficiency  is 67.65 %

and

power output  = work / time

power output  =  1.4 × 10^10 / 3600 sec

power output = 3.88 × 10^6 W

power output = 3.88 × 10^6 W / 746 hp

so power output is 5.20 × 10^3 hp

5 0
3 years ago
One of the waste products of a nuclear reactor is plutonium-239 . This nucleus is radioactive and decays by splitting into a hel
Gekata [30.6K]

Answer:

a) v_{U-235} = 2.68 \cdot 10^{5} m/s

v_{He-4} = -1.57 \cdot 10^{7} m/s  

b) E_{He-4} = 8.23 \cdot 10^{-13} J

E_{U-235} = 1.41 \cdot 10^{-14} J

 

Explanation:

Searching the missed information we have:                                        

E: is the energy emitted in the plutonium decay = 8.40x10⁻¹³ J

m(⁴He): is the mass of the helium nucleus = 6.68x10⁻²⁷ kg  

m(²³⁵U): is the mass of the helium U-235 nucleus = 3.92x10⁻²⁵ kg            

a) We can find the velocities of the two nuclei by conservation of linear momentum and kinetic energy:

Linear momentum:

p_{i} = p_{f}

m_{Pu-239}v_{Pu-239} = m_{He-4}v_{He-4} + m_{U-235}v_{U-235}

Since the plutonium nucleus is originally at rest, v_{Pu-239} = 0:

0 = m_{He-4}v_{He-4} + m_{U-235}v_{U-235}  

v_{He-4} = -\frac{m_{U-235}v_{U-235}}{m_{He-4}}    (1)

Kinetic Energy:

E_{Pu-239} = \frac{1}{2}m_{He-4}v_{He-4}^{2} + \frac{1}{2}m_{U-235}v_{U-235}^{2}

2*8.40 \cdot 10^{-13} J = m_{He-4}v_{He-4}^{2} + m_{U-235}v_{U-235}^{2}    

1.68\cdot 10^{-12} J = m_{He-4}v_{He-4}^{2} + m_{U-235}v_{U-235}^{2}   (2)    

By entering equation (1) into (2) we have:

1.68\cdot 10^{-12} J = m_{He-4}(-\frac{m_{U-235}v_{U-235}}{m_{He-4}})^{2} + m_{U-235}v_{U-235}^{2}  

1.68\cdot 10^{-12} J = 6.68 \cdot 10^{-27} kg*(-\frac{3.92 \cdot 10^{-25} kg*v_{U-235}}{6.68 \cdot 10^{-27} kg})^{2} +3.92 \cdot 10^{-25} kg*v_{U-235}^{2}  

Solving the above equation for v_{U-235} we have:

v_{U-235} = 2.68 \cdot 10^{5} m/s

And by entering that value into equation (1):

v_{He-4} = -\frac{3.92 \cdot 10^{-25} kg*2.68 \cdot 10^{5} m/s}{6.68 \cdot 10^{-27} kg} = -1.57 \cdot 10^{7} m/s                        

The minus sign means that the helium-4 nucleus is moving in the opposite direction to the uranium-235 nucleus.

b) Now, the kinetic energy of each nucleus is:

For He-4:

E_{He-4} = \frac{1}{2}m_{He-4}v_{He-4}^{2} = \frac{1}{2} 6.68 \cdot 10^{-27} kg*(-1.57 \cdot 10^{7} m/s)^{2} = 8.23 \cdot 10^{-13} J

For U-235:

E_{U-235} = \frac{1}{2}m_{U-235}v_{U-235}^{2} = \frac{1}{2} 3.92 \cdot 10^{-25} kg*(2.68 \cdot 10^{5} m/s)^{2} = 1.41 \cdot 10^{-14} J

 

I hope it helps you!                                                                                    

3 0
3 years ago
Other questions:
  • As a bat flies toward a wall at a speed of 6.0 m/s, the bat emits an ultrasonic sound wave with frequency 30.0 kHz. What frequen
    13·1 answer
  • Consider your desk at rest on your bedroom floor. As you and your friend start to lift it, does the support force on the desk pr
    9·1 answer
  • Two fully charged cylindrical capacitors are connected to two identical batteries. The capacitors are identical except that the
    15·1 answer
  • a custodian pulls a vacuum 13.5 m with a 33.9 N force at a 55.0 degree angle , against a 14.2 N friction force . find the work d
    9·1 answer
  • Explain Why must a cooling system do work to transfer thermal energy?
    12·1 answer
  • organisims that have a physical trait that makes it easier for them o access food supply are unlikely to pass on that trait to t
    14·1 answer
  • Please need help on this
    15·1 answer
  • A 250 kg engine block is being dragged across the pavement by a sturdy chain with a tension force of 10,000 N, as seen in the fr
    11·1 answer
  • Classify the statement below as either Speed or Velocity?
    12·1 answer
  • Diverse crops can become vulnerable to pests, disease, and climate change. Which part of this statement is false?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!