The picture below was taken in the Maldives.

How much thermal energy is created when a 3000 kg suv brakes to a stop from 20 m/s on a level road?

JulsSmile [24]

Answer:

b. 600,000 J

Explanation:

Applying the law of conservation of energy,

The thermal energy created = Kinetic energy of the suv.

Q' = 1/2(mv²)............... Equation 1

Where Q' = Thermal energy, m = mass of the suv, v = velocity of the suv.

From the question,

Given: m = 3000 kg, v = 20 m/s

Substitute these values into equation 1

Q' = 1/2(3000×20²)

Q' = 600000 J

Hence the right option is b. 600,000 J

5 0

2 years ago

A resistor of 5 Ω is placed in a circuit. The voltage drop across the resistor is 12 V. What is the current through the resistor

Kaylis [27]

Data:

R = 5 Ω
U = 12 V
i = ?

Formula:

 $U = R*i$ → $i = \frac{U}{R}$ 

Solving:

 $i = \frac{U}{R}$
$i = \frac{12}{5}$
$\boxed{i = 2.4A}$

Answer:

The current through the resistor is 2.4 Amperes

5 0

2 years ago

With which part of the brain is awareness typically associated?

weeeeeb [17]

Answer:cerebral cortex

Explanation:

4 0

2 years ago

Read 2 more answers

A confined aquifer with a porosity of 0.15 is 30 m thick. The potentiometric surface elevation at two observation wells 1000 m a

AlekseyPX

Answer:

Part (a) The flow rate per unit width of the aquifer is 1.0875 m³/day

Part (b) The specific discharge of the flow is 0.0363 m/day

Part (c) The average linear velocity of the flow is 0.242 m/day

Part (d) The time taken for a tracer to travel the distance between the observation wells is 4132.23 days = 99173.52 hours

Explanation:

Part (a) the flow rate per unit width of the aquifer

From Darcy's law;

$q = -Kb\frac{dh}{dl}$

where;

q is the flow rate

K is the permeability or conductivity of the aquifer = 25 m/day

b is the aquifer thickness

dh is the change in th vertical hight = 50.9m - 52.35m = -1.45 m

dl is the change in the horizontal hight = 1000 m

q = -(25*30)*(-1.45/1000)

q = 1.0875 m³/day

Part (b) the specific discharge of the flow

$V = \frac{Q}{A} = \frac{q}{b} = -K\frac{dh}{dl}\\\\V = -(25 m/d).(\frac{-1.45 m}{1000 m}) = 0.0363 m/day$

V = 0.0363 m/day

Part (c) the average linear velocity of the flow assuming steady unidirectional flow

Va = V/Φ

Φ is the porosity = 0.15

Va = 0.0363 / 0.15

Va = 0.242 m/day

Part (d) the time taken for a tracer to travel the distance between the observation wells

The distance between the two wells = 1000 m

average linear velocity = 0.242 m/day

Time = distance / speed

Time = (1000 m) / (0.242 m/day)

Time = 4132.23 days

$= 4132.23 days *\frac{24 .hrs}{1.day} = 99173.52, hours$

4 0

2 years ago

Problem:

Mars2501 [29]

I do have a couple ideas and tips that may help you win. I don’t know how the guidelines are set up so if the ideas won’t be helpful I apologize.

First off put some ice cubes in the container then sprinkle salt on them, The reaction will create an effect and be super cold.

Another idea would be to get some dry ice if you able to, This will freeze it solid within seconds.

The last idea combines the the first. Take a bowl and fill it with with water and ice (Make sure the bowl is insulated) add a small handful of salt into the bowl, Put your drink into the cooler and before shutting stir then well then close and wait for the amount of time left, Your should have a cold water bottle.

I hoped this helped you out and I hope you also win the contest.

8 0

2 years ago