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2 years ago

Find the focal length of a lens of power-2.0D . What type of lens is this ?

Physics

1 answer:

olga_2 [115]2 years ago

3 0

Answer: f = - 0.50 m, negative (diverging) lens

Explanation: D-value (diopter ) means 1/f, unit is 1/m. Thus -2.0D

Means f = ( 1/ -2.0 ) m = -0.50 m

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One way to measure g on another planet or moon by remote sensing is to measure how long it takes an object to fall a given dista

devlian [24]

Answer:

2.24 m/s²

Explanation:

Using equation of motion

s = ut + $\frac{1}{2}$ at²

u = 0 , t = 3.17 s , s = 11.26 m

Put these values in the equation above

11.26 = 0 +.5 x a( 3.17)²

a = 2.24 ms⁻².

So acceleration due to gravity on that planet will be 2.24 m s⁻².

7 0

3 years ago

The tibia is a lower leg bone (shin bone) in a human. The maximum strain that the tibia can experience before fracturing corresp

IRISSAK [1]

Answer:

$k = 11600000 N/m$

$\Delta L = 3.2323 *10^{-5} \ m$

$F = 3750.28 \ N$

Explanation:

From the question we are told that

The Young modulus is $E = 1.4 *10^{10} \ N/m^2$

The length is $L = 0.35 \ m$

The area is $2.9 \ cm^2 = 2.9 *10^{-4} \ m ^2$

Generally the force acting on the tibia is mathematically represented as

$F = \frac{E * A * \Delta L }{L}$ derived from young modulus equation

Now this force can also be mathematically represented as

$F = k * \Delta L$

$k = \frac{E * A }{L}$

substituting values

$k = \frac{1.4 *10^{10} * 2.9 *10^{-4} }{ 0.35}$

$k = 11600000 N/m$

Since the tibia support half the weight then the force experienced by the tibia is

$F_k = \frac{750 }{2} = 375 \ N$

From the above equation the extension (compression) is mathematically represented as

$\Delta L = \frac{ F_k * L }{ A * E }$

substituting values

$\Delta L = \frac{ 375 * 0.35 }{ (2.9 *10^{-4}) * 1.4*10^{10} }$

$\Delta L = 3.2323 *10^{-5} \ m$

From the above equation the maximum force is

$F = \frac{1.4*10^{10} * (2.9*10^{-4}) * 3.233*10^{-5} }{ 0.35}$

$F = 3750.28 \ N$

4 0

3 years ago

What is the speed of an object that moves from 70 m to 68 m in 14 s?

PtichkaEL [24]

Speed = m/s
Velocity can be negative, but speed cannot.

70 - 68 = 2
2/14 = 0.143 m/s

5 0

3 years ago

A car moved 40 km north and 90 km south. What is the displacement of the car?

il63 [147K]

Answer:

A. 50 km south

Explanation:

hope this helps!

8 0

3 years ago

a stone is thrown horizonttaly from a cliff of a hill with an initial velocity of 30m/s it hits the ground at a horizontal dista

ELEN [110]

Answer:

a) Time = 2.67 s

b) Height = 35.0 m

Explanation:

a) The time of flight can be found using the following equation:

$x_{f} = x_{0} + v_{0_{x}}t + \frac{1}{2}at^{2}$ (1)

Where:

$x_{f}$ : is the final position in the horizontal direction = 80 m

$x_{0}$ : is the initial position in the horizontal direction = 0

$v_{0_{x}}$ : is the initial velocity in the horizontal direction = 30 m/s

a: is the acceleration in the horizontal direction = 0 (the stone is only accelerated by gravity)

t: is the time =?

By entering the above values into equation (1) and solving for "t", we can find the time of flight of the stone:

$t = \frac{x_{f}}{v_{0}} = \frac{80 m}{30 m/s} = 2.67 s$

b) The height of the hill is given by:

$y_{f} = y_{0} + v_{0_{y}}t - \frac{1}{2}gt^{2}$

Where:

$y_{f}$ : is the final position in the vertical direction = 0

$y_{0}$ : is the initial position in the vertical direction =?

$v_{0_{y}}$ : is the initial velocity in the vertical direction =0 (the stone is thrown horizontally)

g: is the acceleration due to gravity = 9.81 m/s²

Hence, the height of the hill is:

$y_{0} = \frac{1}{2}gt^{2} = \frac{1}{2}9.81 m/s^{2}*(2.67 s)^{2} = 35.0 m$

I hope it helps you!

5 0

3 years ago