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Liono4ka [1.6K]

3 years ago

8

Read the following experiment. Describe the experiment's results; identify which of Newton's laws is illustrated and how these r

esults support this law.
1. Place a 3X5 card on top of a glass
2. Put a coin on the center of the card.
3. Flick the card horizontally with your finger
4. What happens to the coin?

1 answer:

Volgvan3 years ago

8 0

It’s 3 guaranteed because if you flick the card horizontal it’s going to bend the laws

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6) A penny is dropped from the roof of a house. The penny is traveling at 35 m/s right before it hits

nadezda [96]

Wait what is m/s?
Can you tell me that so i could help

8 0

3 years ago

You set your stationary bike on a high 80-N friction-like resistive force and cycle for 30 min at a speed of 8.0 m/s . Your body

stellarik [79]

A) The change in internal chemical energy is $1.15\cdot 10^7 J$

B) The time needed is 1 minute

Explanation:

First of all, we start by calculating the power output of you and the bike, given by:

$P=Fv$

where

F = 80 N is the force that must be applied in order to overcome friction and travel at constant speed

v = 8.0 m/s is the velocity

Substituting,

$P=(80)(8.0)=640 W$

The energy output is related to the power by the equation

$P=\frac{E}{t}$

where:

P = 640 W is the power output

E is the energy output

$t = 30 min \cdot 60 = 1800 s$ is the time elapsed

Solving for E,

$E=Pt=(640)(1800)=1.15\cdot 10^6 J$

Since the body is 10% efficient at converting chemical energy into mechanical work (which is the output energy), this means that the change in internal chemical energy is given by

$\Delta E = \frac{E}{0.10}=\frac{1.15\cdot 10^6}{0.10}=1.15\cdot 10^7 J$

B)

From the previous part, we found that in a time of

t = 30 min

the amount of internal chemical energy converted is

$E=1.15\cdot 10^7 J$

Here we want to find the time t' needed to convert an amount of chemical energy of

$E'=3.8\cdot 10^5 J$

So we can setup the following proportion:

$\frac{t}{E}=\frac{t'}{E'}$

And solving for t',

$t'=\frac{E't}{E}=\frac{(3.8\cdot 10^5)(30)}{1.15\cdot 10^7}=1 min$

Learn more about power and energy:

brainly.com/question/7956557

#LearnwithBrainly

3 0

3 years ago

How many atoms are in 3.5 moles of sulfur

irina [24]

There are 2.1077x10^24 atoms of sulfur in 3.50 mols of sulfur.

5 0

3 years ago

A circle has an initial radius of 50ft when the radius begins decreasing at a rate of 2ft/s. what is the rate of change of the a

valkas [14]

The area of the circle with radius r is
A = πr²

The rate of change of area with respect to time is
$\frac{dA}{dt} = \frac{dA}{dr} . \frac{dr}{dt} =2 \pi r. \frac{dr}{dt}$

The rate of change of the radius is given as
$\frac{dr}{dt} =-2 \, \frac{ft}{s}$
Therefore
$\frac{dA}{dt} =-4 \pi r \, \frac{ft^{2}}{s}$

When r = 10 ft, obtain
$\frac{dA}{dt}|_{r=10 \, ft} = -40 \pi \, \frac{ft^{2}}{s}$

Answer: - 40π ft²/s (or - 127.5 ft²/s)

7 0

3 years ago

1)the car's engine power is 44000W. Explain this number in a physical sense

Ratling [72]

Answer:

1) It expresses the rate (top speed) at which it can move with time.

2) P = 20 W

3) h = 18 km

Explanation:

1) Power is the rate of transfer of energy.

⇒ Power = $\frac{Energy(or workdone)}{Time}$

i.e P = $\frac{E}{t}$

Thus a car's engine power is 44000W implies that the engine of the car can propel the car at this rate. This expresses the rate (top speed) at which it can move with time.

2) m = 400g = 0.4 kg

t = 20 s

h = 100m

g = 10 m/ $s^{2}$

P = $\frac{mgh}{t}$

= $\frac{0.4*10*100}{20}$

= $\frac{400}{20}$

P = 20 W

3) u = 600 m/s

g = 10 m/ $s^{2}$

From the third equation of free fall,

$V^{2}$ = $U^{2}$ - 2gh

V is the final velocity, U is the initial velocity, h is the height.

0 = $(600)^{2}$ - 2 x 10 x h

0 = 360000 - 20h

20h = 360000

h = $\frac{360000}{20}$

= 18000

h = 18 km

The maximum height of the bullet would be 18 km.

3 0

3 years ago