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Free_Kalibri [48]

2 years ago

11

Pravat exerts a force of 30 n to lift a bag of groceries 0.5 m. how much work did pravat do on the bag? note : work = force x di

stance 0 j 15 j 30 j 60 j

2 answers:

AURORKA [14]2 years ago

7 0

Answer:

he is right it’s D

Explanation:

if u could not read his hand writing

ss7ja [257]2 years ago

6 0

Answer in photo below

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The force of gravity on the moon is only 16.6% the force of gravity on Earth. For each item listed in the table below, fill in w

Dmitry [639]

==> Take an Earth weight. Don't forget the unit.

==> Multiply it by 0.166 .

==> The product is its Moon weight. Don't forget the unit.

Example:

If I weigh 1,000 lbs on Earth.

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I weigh 166 lbs on the Moon

4 0

3 years ago

Aconstant current of 3 Afor 4 hours is required to charge an automotive battery. If the terminal voltage is V, where t is in hou

kirza4 [7]

Answer:

(a) 43.2 kC

(b) 0.012V kWh

(c) 0.108V cents

Explanation:

<u>Given:</u>

i = current flow = 3 A
t = time interval for which the current flow = $4\ h = 4\times 3600\ s = 14400\ s$
V = terminal voltage of the battery
R = rate of energy = 9 cents/kWh

<u>Assume:</u>

Q = charge transported as a result of charging
E = energy expended
C = cost of charging

Part (a):

We know that the charge flow rate is the electric current flow through a wire.

$\therefore i = \dfrac{Q}{t}\\\Rightarrow Q =it\\\Rightarrow Q = 3\times 14400\\\Rightarrow Q = 43200\ C\\\Rightarrow Q = 43.200\ kC\\$

Hence, 43.2 kC of charge is transported as a result of charging.

Part (b):

We know the electrical energy dissipated due to current flow across a voltage drop for a time interval is given by:

$E = Vit\\\Rightarrow E = V\times 3\times 4\\\Rightarrow E = 12V\ Wh\\\Rightarrow E = 0.012V\ kWh\\$

Hence, 0.012V kWh is expended in charging the battery.

Part (c):

We know that the energy cost is equal to the product of energy expended and the rate of energy.

$\therefore \textrm{Cost}=\textrm{Energy}\times \textrm{Rate}\\\Rightarrow C = ER\\\Rightarrow C = 0.012V\times 9\\\Rightarrow C =0.108V\ cents$

Hence, 0.108V cents is the charging cost of the battery.

4 0

4 years ago

What are the benefits and harms of protists? WILL GIVE BRAINLIEST FOR THE PERFECT ANSWER

alina1380 [7]

Answer:

<em>Well, Many protists are harmful to humans, other animals and plants because they cause diseases and crop failures. However, some protists are actually beneficial to other creatures and are used by humans for various purposes. Plant-like protists produce almost one-half of the oxygen on the planet through photosynthesis. Other protists decompose and recycle nutrients that humans need to live. For example, medicines made from protists are used in treatment of high blood pressure, digestion problems, ulcers, and arthritis. Hope That Helps!</em>

<em>From ~Itsbrazts~. Have a Great Day!</em>

6 0

3 years ago

Read 2 more answers

A car moves at a constant velocity of 30 m/s and has 3.6 × 105 J of kinetic energy. The driver applies the brakes and the car st

LekaFEV [45]

The force needed to the stop the car is -3.79 N.

Explanation:

The force required to stop the car should have equal magnitude as the force required to move the car but in opposite direction. This is in accordance with the Newton's third law of motion. Since, in the present problem, we know the kinetic energy and velocity of the moving car, we can determine the mass of the car from these two parameters.

So, here v = 30 m/s and k.E. = 3.6 × 10⁵ J, then mass will be

$K.E = \frac{1}{2} * m*v^{2} \\\\m = \frac{2*KE}{v^{2} } = \frac{2*3.6*10^{5} }{30*30}=800 kg$

Now, we know that the work done by the brake to stop the car will be equal to the product of force to stop the car with the distance travelled by the car on applying the brake.Here it is said that the car travels 95 m after the brake has been applied. So with the help of work energy theorem,

Work done = Final kinetic energy - Initial kinetic energy

Work done = Force × Displacement

So, Force × Displacement = Final kinetic energy - Initial Kinetic energy.

$Force * 95 = 0-3.6*10^{5}\\ \\Force =\frac{-3.6*10^{5} }{95}=-3.79 N$

Thus, the force needed to the stop the car is -3.79 N.

5 0

3 years ago

mestny [16]

Answer:

false

A hypothesis states a presumed relationship between two variables in a way that can be tested with empirical data. ... The cause is called the independent variable; and the effect is called the dependent variable.

6 0

3 years ago