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Alexxx [7]
3 years ago
11

An energy-saving light bulb has an efficiency of 45%. If 5W of light is emitted, what electrical power is required

Physics
1 answer:
Gwar [14]3 years ago
3 0

Answer:

If you're using the bulb as a source of light, then it's. 14/60 = 23.3% efficient.

If you're using it to heat a bird nest or a hamster cage, then it's. 46/60 = 76.7% efficient !

It just depends on your point of view, and what you consider 'useful' output.

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What is a measure between the difference in start and end positions?
crimeas [40]

Answer:

Displacement

General Formulas and Concepts:

<u>Kinematics</u>

  • Displacement vs Total Distance

Explanation:

Displacement is the difference between the start position and end position.

Total Distance is the entire distance <em>traveled</em> between the start and end position.

Topic: AP Physics 1 Algebra-Based

Unit: Kinematics

5 0
3 years ago
Two automobiles of equal mass approach an intersection. One vehicle is traveling with velocity 14.0 m/s toward the east and the
Sergeeva-Olga [200]

Answer:

kqwwwwj

Explanation:

4 0
3 years ago
When iron rusts, iron atoms are destroyed true or false?
vfiekz [6]
False. this is just a physical change, not a chemical change. 
3 0
3 years ago
The breaking car had 10,000 J of kinetic energy before breaking after breaking it had 2000 J of kinetic energy. How much thermal
WINSTONCH [101]

Answer:

8000J

Explanation:

The kinetic energy of the car lost during breaking are converted to thermal energy and are gained by the brakes.

Kinetic energy loss by car = thermal energy gained by brakes.

∆K.E = ∆T.E ....1

The Kinetic energy loss by car can be expressed as;

∆K.E = K.E1 - K.E2

Initial K.E = K.E1 = 10000J

Final K.E = K.E2 = 2000J

∆K.E= 10000J - 2000J = 8000J

From equation 1,

∆K.E = ∆T.E

∆T.E = 8,000J

thermal energy gain by brakes = 8,000J

8 0
3 years ago
A projectile is fired at an upward angle of 45.0º from the top of a 265-m cliff with a speed of .sm 185 What will be its speed w
nignag [31]

The final velocity of the projectile when it strikes the ground below is 198.51 m/s.

<h3>Time of motion of the projectile</h3>

The time taken for the projectile to fall to the ground is calculated as follows;

h = vt + ¹/₂gt²

where;

  • h is height of the cliff
  • v is velocity
  • t is time of motion

265 = (185 x sin45)t + (0.5)(9.8)t²

265 = 130.8t + 4.9t²

4.9t² + 130.8t - 265 = 0

solve the quadratic equation using formula method,

t = 1.89 s

<h3>Final velocity of the projectile</h3>

vyf = vyi + gt

where;

  • vyf is the final vertical velocity
  • vyi is initial vertical velocity

vyf = (185 x sin45) + (9.8 x 1.89)

vyf = 149.322 m/s

vxf = vxi

where;

  • vxf is the final horizontal velocity
  • vxi is the initial horizontal velocity

vxf = 185 x cos(45)

vxf = 130.8 m/s

vf = √(vyf² + vxf²)

where;

  • vf is the speed of the projectile when it strikes the ground below

vf = √(149.322²  +  130.8²)

vf = 198.51 m/s

Learn more about final velocity here: brainly.com/question/6504879

#SPJ1  

3 0
2 years ago
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