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3 years ago

Why does the lens need to be thicker for viewing nearby objects?

1 answer:

5 0

Answer: To focus on a near object – the lens becomes thicker, this allows the light rays to refract (bend) more strongly. To focus on a distant object – the lens is pulled thin, this allows the light rays to refract slightly.

Explanation:

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A race car accelerates uniformly at 14.2 m/s2. If the race car starts from rest how fast will it

Kaylis [27]

Answer:

vf=94.4 m/s

Explanation:

acceleration is the final velocity minus initial velocity divided by time

a = (vf-vi)/t

Given:

a= 14.2 m/s^2

vi= 0 (at rest)

t = 6.6

Solve for vf

a = (vf-vi)/t

a*t=vf-vi

(14.2)*(6.6)=vf - 0

vf=94.4 m/s

6 0

3 years ago

A fountain can hold 53,000 deciliters of water. how many kiloliters is this ?

zubka84 [21]

5.3 kiloliters is how much water a fountain can hold.

3 0

4 years ago

True or false: Waves transfer matter as they travel.

Natalija [7]

Answer: false

Explanation: hope that helped

4 0

3 years ago

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A concrete highway is built of slabs 12 m long .How wide should be the expansion cracks between the slabs at 15 Celsius to preve

morpeh [17]

Answer:

$x=4.2\ mm$

Explanation:

Given:

length of the concrete slab, $l=12\ m$

temperature of observation, $T_o=15^{\circ}C$

we've the coefficient of linear expansion for concrete, $\alpha=10^{-5}\ ^{\circ}C^{-1}$

lower temperature limit, $T_l=-30^{\circ}C$

upper temperature limit, $T_u=50^{\circ}C$

<u>Change in length due to temperature can be given as:</u>

$\Delta l=l.\alpha.(T_u-T_l)$

$\Delta l=12\times 10^{-5}\times (50-(-30))$

$\Delta l=0.0096\ m=9.6\ mm$

<u>Now at temperature 15°C:</u>

$\Delta l'=12\times 10^{-5}\times (15-(-30))$

$\Delta l'=0.0054\ m=5.4\ mm$

Hence the expansion crack between the slabs at this temperature must be:

$x=\Delta l-\Delta l'$

$x=9.6-5.4$

$x=4.2\ mm$

3 0

3 years ago

A skier reaches the end of a 0.9 km track in 1.5 hours, at what speed does it travel?

Wewaii [24]

Speed = Distance/Time

S = D/T

D = 0.9Km, T = 1.5hours,

S = 0.9/1.5

S = 0.6 m/s

hope it helps!

7 0

4 years ago

Read 2 more answers