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
EastWind [94]
2 years ago
12

An electric motor takes 30 s to lift a box of mass 45 000g to a height of 1.7 m. Calculate the power of the electric motor.

Physics
1 answer:
Sidana [21]2 years ago
3 0

Power P is the amount of energy E transferred or converted per unit time t, and is expression is:

P = E/t

The necessary energy to lift the box its the work of against the Gravity Force, and is given by:

E = mgh

Then the power is:

P = E/t

P = mgh/t

P = (45 kg)(9.8 m/s²)(1.7 m )/ 30

P = 24.99 W

<h2>P ≈ 25 W</h2>
You might be interested in
1. When an object's distance from another object is changing it must be
slega [8]
An object is in motion if its distance from another object is changing. An object is in motion if it changes position relative to a reference point. An reference point is a place or object used for comparison to determine if something is moving.
3 0
3 years ago
Explain how land breeze and sea breezes occur?
marshall27 [118]

Explanation:

during the daytime the land gets hot and the hot air blows up to the sky and to feel the space the cool you are from the Sea blows to the land this phenomenon is called sea breeze similarly at night the hot air of sea goes up n cool air from land blows to sea which is called land breexe

please mark me the brainliest

5 0
2 years ago
Read 2 more answers
If you wanted the pitch of a horn to drop relative to an observer, which way would you move the horn, relative to where that obs
Vladimir [108]
We assume that horn releases sound of constant frequency. In order for observer to observe different frequency either horn or observer or both must move.

This happens due to Doppler effect. It states that when position of source of sound and observer relative to each other changes, the observed frequency also changes. If the source emits sound of constant frequency than observed frequency will be either higher or lower than original.

When distance between source and observer increases the observed frequency will be lower. This is because same number of sound waves must cover greater distance so they have greater wavelength.
When distance between source and observer decreases the observed frequency will be higher. This is because same number of sound waves must cover smaller distance so they have smaller wavelength. 

Wavelength and frequency are inversely proportional meaning when one increases the other drecreases.

From this explanation we can find answer for our question. <span>If we wanted the pitch of a horn to drop relative to an observer we need to move horn away from an observer.</span>
3 0
2 years ago
1.Calculate the energy transferred by a 12V hairdryer, running on a current of 0.50A, that is left on for 8.0 minutes.
CaHeK987 [17]

Answer:

1. Energy = 2880 Joules.

2. Energy = 60 Joules.

3. Quantity of charge = 120 Coulombs.

Explanation:

Given the following data;

1. Voltage = 12 Volts

Current = 0.5 Amps

Time, t = 8 mins to seconds = 8 * 60 = 480 seconds

To find the energy;

Power = current * voltage

Power = 12 * 0.5

Power = 6 Watts

Next, we find the energy transferred;

Energy = power * time

Energy = 6 * 480

Energy = 2880 Joules

2. Charge, Q = 4 coulombs

Potential difference, p.d = 15V

To find the total energy transferred;

Energy = Q * p.d

Energy = 4 * 15

Energy = 60 Joules

3. Voltage = 6 Volts

Current = 1 Amps

Time = 2 minutes to seconds = 2 * 60 = 120 seconds

To find the quantity of charge;

Quantity of charge = current * time

Quantity of charge = 1 * 120

Quantity of charge = 120 Coulombs

8 0
3 years ago
Two identical resistors connected in series have an equivalent resistance of 4 ohms. The same two resistors, when connected in p
irina1246 [14]

Answer:

1 ohm

Explanation:

since there are two identical resistors, one resistor will be

R = \frac{4}{2} =2ohm [ proven as in series R_{e} = 2 + 2 = 4ohm ]

to calculate the equivalent resistance when in parallel:

\frac{1}{R_{e} }  = \frac{1}{R_{1} } + \frac{1}{R_{2}}

so,

\frac{1}{R_{e} } = \frac{1}{2} + \frac{1}{2}

R_{e} = 1ohm

4 0
2 years ago
Other questions:
  • A cylinder 0.170 m in diameter rotates in a lathe at 530 rpm . what is the tangential speed of the surface of the cylinder?
    12·1 answer
  • A volleyball player’s hand applies a 39 N force while in contact with a volleyball for 2 seconds. What is the impulse on the bal
    9·2 answers
  • A sled is moving down a steep hill. The mass of the sled is 50 kg and the net force acting on it is 20 N. What must be done to f
    7·2 answers
  • Can animal cells be broken down further into a living unit
    10·2 answers
  • A scientist found a new bacteria in a hot water sulfur spring that uses sulfur as a source of energy instead sunlight. What kind
    15·1 answer
  • Fuel cells have been developed that can generate a large amount of energy. For example, a hydrogen fuel cell works by combining
    15·1 answer
  • The kinetic energy of a baseball is doubled by changing the speed of the baseball. By what factor has its speed changed? √ 2 v i
    14·1 answer
  • Suppose the electric company charges 10 fils per kW h. How much does it cost to use a 125 watt lamp 4 hours a day for 30 days? A
    11·1 answer
  • A ceiling fan has three blades. The moment of inertia of a blade is 0.2kgm^2. The net torque exerted on fan blades is 8Nm. Find
    11·1 answer
  • 11. A disk 8.00 cm in radiu: rotates at a constant rate of 1200 revinin about its central axis Determine (a) its angular speed i
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!