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3 years ago

Which two statements are true about energy transformations?

1 answer:

8 0

Energy is never created nor destroyed

So your answer is Energy is never created
and Energy is never destroyed

Hope this helps :)

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It is 6.00 km from your home to the physics lab. as part of your physical fitness program, you could run that distance at 10.0 k

kirill115 [55]

<span>1.) It is 6.00km from your home to the physics lab. As part of your physical fitness program, you could run that distance at 10.0km/hr (which uses up energy at the rate of 700W ), or you could walk it leisurely at 3.00km/hr (which uses energy at 290 W). A.)Which choice would burn up more energy? running or walking? b.)How much energy (in joules) would it burn? c.)Why is it that the more intense exercise actually burns up less energy than the less intense one? Follow 2 answers Report Abuse Answers billrussell42 Best Answer: running, at 10 km/hour for 6 km is 6 km / 10 km/hour = 0.6 hour or 36 min energy used is 700 watts or 700 joules/s x 36 min x 60s/min = 1.512e6 joules or 1.5 MJ walking, at 3 km/hour for 6 km 6 km / 3 km/hour = 2 hour or 120 min energy used is 290 watts or 290 joules/s x 120 min x 60s/min = 1.872e6 joules or 1.8 MJ C) should be obvious PS, this has nothing to do with potential energy. billrussell42 Â· 5 years ago 0 Thumbs up 1 Thumbs down Report Abuse Comment Simon van Dijk I assume the watt consumption is per hour. Then running 6km at 10.0 km/h results in 700*6/10 = 420 w.h and walking in 290*6/3 = 580 w.h So walking would burn up more energy (kwh) b) 1 kilowatt hour = 3 600 000 joules so 420 wh = 0.42 kwh = 1.51.10^6 joule c) when you put more effort in making the distance your energy is used more efficient. Simon van Dijk Â· 5 years ago 0 Thumbs up 2 Thumbs down Report Abuse Comment</span>

7 0

2 years ago

Sand is pouring out of a pipe and is forming a conical pile on the ground. The radius of the pile is increasing at a rate of 2 f

Anton [14]

Answer:

$a)\ V=3053.628059 \ ft^3$

$b)\ V'=1017.876\ ft^3/day$

Explanation:

<u>Rate of Change</u>

The volume of a cone of radius r and height h is given by

$\displaystyle V=\frac{\pi r^2h}{3}$

The height is said to be 1/2 of the radius, thus

$\displaystyle V=\frac{\pi r^2\cdot r}{2\cdot 3}$

$\displaystyle V=\frac{\pi r^3}{6}$

a) Knowing r=18 feet, the volume is

$\displaystyle V=\frac{\pi 18^3}{6}$

$V=3053.628059 \ ft^3$

b) The rate of change of the volume is computed by taking the derivative of both sides respect to the time

$\displaystyle V'=3\frac{\pi r^2}{6}r'$

$\displaystyle V'=\frac{\pi r^2}{2}r'$

Where r' is the given rate of change of the radius: 2 feet/day.

Now we compute

$\displaystyle V'=\frac{\pi 18^2}{2}\cdot 2=1017.876$

$\boxed{V'=1017.876\ ft^3/day}$

6 0

3 years ago

Suppose you are in a moving car and the motor stops running. You step on the brakes and slow the car to half speed. If you relea

In-s [12.5K]

Answer:

See the answer below

Explanation:

If you step on the brake of a car while driving, the frictional force between the tires of the car and the surface of the road increases in opposition to the motion of the car. Consequently, the car slows down.

If you release your foot from the brake pedal when the car is still at half speed, the frictional force reduces and the car speeds up a bit even without pressing the throttle. Eventually, the frictional force will slow down and stop the car if the throttle is not pressed.

4 0

2 years ago

We can estimate the age of an open cluster of stars by examining _________.

ololo11 [35]

I think the answer is C

Hope this help

5 0

3 years ago

A force of 35 n acts on an object which has a mass of 5.4 kg. what acceleration (in m/s2) is produced by the force

galina1969 [7]

∑F = ma
a = ∑F/m
a = 35 N / 5.4 kg
a = 6.5 m/s²

4 0

2 years ago