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3 years ago

When the Egyptians noticed this celestial body rising before the Sun it indicated to them the coming of the Nile flood.

Physics

1 answer:

ahrayia [7]3 years ago

6 0

Answer:

when the ancient egyptians noticed the rising of sirius (brightest start on the night sky) before the sun it indicated to them the coming of the nile flood.

Explanation:

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Julie throws a ball to her friend Sarah. The ball leaves Julie's hand a distance 1.5 meters above the ground with an initial spe

iris [78.8K]

Answer:

Explanation:

1. $V_{x}$ = $V_{0}$ * cos $\alpha$ ⇒ 16*cos32 ≈ 13.6 m/s (13.56)

2. $V_{y}$ = $V_{0}$ * sin $\alpha$ ⇒ 16* sin32 ≈ 9.4 m/s

3. $y_{max}$ = $\frac{v_{0}^2*sin^2\alpha}{2g}$ = $\frac{16^2*sin^232}{2*9.8}$ (the g (gravity) depends on the country but i'll take the average g which is 9.2m/s^2)

$y_{max}$ ≈ 3.6677+1.5 ≈ 5.2m

4. $x_{max}$ = $\frac{v_{0}^2*sin(2\alpha)}{g}$ = $\frac{16^2*sin(2*32)}{9.8}$ ≈ 23.5m (23.47)

5. -

answer 4 could be wrong, not certain about that one and i don't know 5

3 0

3 years ago

A machine exerts a 100 N force to the right over a 5.00 meter length in 4.00 seconds. Calculate the power output of this machine

bixtya [17]

125 W is the power output of this machine.

Answer:

Explanation:

Power is defined as the amount of work done on the system to move that system from its original state within the given time interval. So it can be determined by the ratio of work done with time interval. As work done is the measure of force required to move a system to a certain distance. Work done is calculated as product of force with displacement.

So in the present case, the force is given as 100 N, the displacement is given as 5 m and the time is given as 4 s, then power is

$Power = \frac{Work done}{Time}$

As Work done = Force acting on the machine × Displacement

So $Power = \frac{(Force * Displacement)}{Time}$

Power = $\frac{(100*5)}{4}$ =125 W

So, 125 W is the power output of this machine.

6 0

3 years ago

A projectile is shot from the edge of a cliff above the ground level with initial velocity of at an angle with the horizontal. (

Xelga [282]

Answer:

t = √2y/g

Explanation:

This is a projectile launch exercise

a) The vertical velocity in the initial instants ( $v_{oy}$ = 0) zero, so let's use the equation

y = $v_{oy}$ t -1/2 g t²

y= - ½ g t²

t = √2y/g

b) Let's use this time and the horizontal displacement equation, because the constant horizontal velocity

x = vox t

x = v₀ₓ √2y/g

c) Speeds before touching the ground

vₓ = vox = constant

$v_{y}$ = $v_{oy}$ - gt

$v_{y}$ = 0 - g √2y/g

$v_{y}$ = - √2gy

tan θ = Vy / vx

θ = tan⁻¹ (vy / vx)

θ = tan⁻¹ (√2gy / vox)

d) The projectile is higher than the cliff because it is a horizontal launch

6 0

4 years ago

A beam is said to be statically determinate if all of its unknown reaction components can be determined by the static equilibriu

BlackZzzverrR [31]

Answer:

The correct option is propped cantilever beam.

Explanation:

A propped cantilever beam along with all the reactions is shown in the attached figure.

Since we can see that the number of unknowns are 4 but the equations of statics are only 3 thus we conclude that the beam is indeterminate to 1 degree.

For all the other beams the reactions and the equations are 3 each thus making the system determinate.

4 0

4 years ago

Bird bones have air pockets in them to reduce their weight–this also gives them an average density significantly less than that

lakkis [162]

Answer:

a)39ml

b)39g

c)1.1g/ml

Explanation:

Hello!

To solve this exercise use the following steps

1. When Archimedes discovered how to determine the irregular volume of an object by weighing it in the air and in an algua, he found that its volume is equal to the ratio between the differences of the masses (heavy in the air and in the water) and the density of the water (= 1g / ml)

$V=\frac{43g-3.6g}{1g/ml} =39.4ml$

2.as the principle of archimedes says, the displaced volume of water is equal to the volume of the bone which means that 39.4ml of water was displaced, taking into account that the density of water is the ratio between mass and volume we can determine the displaced body of water

$density=\frac{m}{V} \\m=V(density)\\m=(39ml)(1g/ml)=39g$

3. we use the density equation to find the bone density

$density=\frac{43g}{39ml} =1.1g/ml$

8 0

3 years ago