What force besides gravity would act on something that had been thrown in the air

A light bulb emitting 1750 Im of luminous flux shines on a book that is 3.0

denis-greek [22]

The illumination of the book is found to be approximately equal to 15 lx.

Option 1.

Explanation:

Luminous flux is the measure of power of the light emitted from a source and illumination is the property of the light to illuminate a given surface when it falls on the surface. So the measure of the region the light flux illuminates the surface is termed as illumination.

As here the luminous flux is given as 1759 lm and the distance of the object which has to be illuminated is placed 3 m away from the source ,the illumination is found to be directly proportional to the luminous flux and inversely proportional to the square of the distance between them

$illumination = \frac{Luminous flux}{4\pi d^{2} } \\\\illumination = \frac{1750}{4*3.14*3*3} = 15.48 lx = 15 lx$

So, the illumination of the book is found to be approximately equal to 15 lx.

5 0

3 years ago

How much heat (in kJ) is needed to convert 866 g of ice at −10°C to steam at 126°C? (The specific heats of ice and steam are 2.0

elena-14-01-66 [18.8K]

Answer:

2671.3 kJ

Explanation:

m = 866 g at - 10 degree C converts into steam at 126 degree C.

The following steps are there

(1) ice at - 10 degree C converts into ice at 0 degree C

H1 = m x specific heat of ice x ΔT

H1 = 866 x 2.03 x 10 = 17579.8 J

(ii) ice at 0 degree C converts into water at 0 degree C

H2 = m x Latent heat of fusion = 866 x 334 = 289244 J

(iii) water at 0 degree C converts into water at 100 degree C

H3 = m x specific heat of water x ΔT

ΔH3 = 866 x 4.186 x 100 = 362507.6 J

(iv) water at 100 degree C converts into steam at 100 degree C

H4 = m x Lateant heat of vaporisation

H4 = 866 x 2260 = 1957160 J

(v) seam at 100 degree C converts into steam at 126 degree C

H5 = m x specific heat of steam x ΔT

H5 = 866 x 1.99 x 26 = 44806.84 J

The total heat required is

H = H1 + H2 + H3 + H4 + H5

H = 2671298.24 J = 2671.3 kJ

8 0

3 years ago

The longest banana split ever made was 7.32 km long (obviously they used more than one banana). If an archer were to shoot an ar

elixir [45]

Answer:

The horizontal displacement of the arrow is not larger than the banana split.

Explanation:

Using y - y₀ = ut - 1/2gt², we find the time it takes the arrow to drop to the ground from the top of mount Everest.

So, y₀ = elevation of Mount Everest = 29029 ft = 29029 × 1ft = 29029 × 0.3048 m = 8848.04 m, y = final position of arrow = 0 m, u = initial vertical speed of arrow = 0 m/s, g = acceleration due to gravity = 9.8 m/s² and t = time taken for arrow to fall to the ground.

y - y₀ = ut - 1/2gt²

0 - y₀ = 0 × t - 1/2gt²

-y₀ = -1/2gt²

t² = 2y₀/g

t = √(2y₀/g)

Substituting the values of the variables, we have

t = √(2y₀/g)

= √(2 × 8848.04 m/9.8 m/s²)

= √(17696.08 m/9.8 m/s²)

= √(1805.72 s²)

= 42.5 s

The horizontal distance the arrow moves is thus d = vt where v = maximum firing speed of arrow = 100 m/s and t = 42.5 s