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3 years ago

In terms of impulse and momentum, why are air bags in automobiles a good idea

1 answer:

5 0

During a car crash, the car decelerates extremely rapidly, so inertia causes you to move forward quickly. If there wasn't an airbag to slow you down, you might fly out the windshield.
The air bag increases impulse by increasing the time during which a force acts on you (impulse=force*time). This decreases your forward momentum, so you'll have a better chance of surviving.

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Does organisms get rid of waste

Strike441 [17]

Bacteria get rid of waste through their semi-permeable membrane by diffusion. The waste is pushed out of the organism in the form of liquid or gas. The waste released by bacteria is usually toxic and is what makes people sick.

3 0

3 years ago

Read 2 more answers

Just about everyone at one time or another has been burned by hot water or steam. This problem compares the heat input to your s

tatyana61 [14]

Answer:

$Q_T=63313.5\ J$

Explanation:

Given:

temperature of skin, $T_s=34^{\circ}C$

initial temperature of steam vapour, $T_v=100^{\circ}C$

latent heat of steam, $L=2256\ J.g^{-1}$

mass of steam, $m=25\ g$

specific heat of water, $c=4190\ J.kg^{-1}.K^{-1}=4.19\ J.g^{-1}.K^{-1}$

final temperature, $T_f=34^{\circ}C$

Assuming that no heat is lost in the surrounding.

We know:

$Q=m.c.\Delta T$

Now the total heat given by the steam to form water at the given conditions:

$Q_T=Q_{Lv}+Q_w$ ..............................(1)

where:

$Q_{Lv}=$ latent heat given out by vapour to form water of 100°C

$Q_w=$ heat given by water of 100°C to come at 34°C.

putting respective values in eq. (1)

$Q_T=m(L+c.\Delta T)$

$Q_T=25(2256+4.19\times 66)$

$Q_T=63313.5\ J$

is the heat transferred to the skin.

4 0

3 years ago

Example of the word médium ?

Ira Lisetskai [31]

I am the medium one that in the family

4 0

3 years ago

A 10 kg blue cart moving to the right at 25 m/s collides with a 17 kg red cart moving in the opposite direction at 16 m/s. If, a

scoray [572]

Answer:

24.8m/s

Explanation:

Given data

m1= 10kg

u1=25m/s

m2=17kg

u2=16m/s

v1=10m/s

v2=??

Applying the conservation of linear momentum

m1u1+m2u2=m1v1+m2v2

substitute

10*25+17*16=10*10+17*v2

250+272=100+17v2

522=100+17v2

522-100=17v2

422=17v2

Divide both sides by 17

v2= 422/17

v2= 24.8 m/s

Hence the velocity of the red cart is 24.8m/s in the opposite direction of the blue cart

3 0

3 years ago

Which list of properties of alternation current is the most likely reason it was chosen over direct current to provide electrici

Paraphin [41]

Answer:

- Direct current is a current in which electrons flow in one direction only

- Alternating current is a current in which the direction of the electron flow reverses periodically - so, half a cycle forward, half a cycle backward

There are several advantages of using alternating currents for the transmission of electricity across a country, over large distances. The main advantages are:

- The voltage of alternating currents can be easily increased/decreased by using transformers. For instance, a transformer is used at the beginning of the transmission line to increase the voltage (electricity is transmitted at high voltage in order to reduce dissipated power), and then another transformer is used before the electricity enters the houses, in order to decrease the voltage. Transformers only work with alternating currents.

- It is easy to interrupt the flow of an alternating current, because its value naturally becomes zero every half a cycle, so this is useful in case the current must be interrupted.

8 0

3 years ago