sir lancelot, who weighs 800 n, is assaulting a castle by climbing a uniform ladder that is 5.0 m long and weighs 180 n. the bottom of the ladder rests on a ledge and leans across the moat in equilibrium against a frictionless, vertical castle wall. the ladder makes an angle of 53.1 deg with the horizontal. lancelot pauses one third of the way up the ladder. (a) find the normal force and friction forces on the base of the ladder. (b) find the minimum coefficient of static friction needed to prevent slipping at the base. (c) find the magnitude and direction of the contact force on the base of the ladder. (that is, the vector sum of the forces at the base.)

sheesh sheesh                                                    

Explanation:

The height of the cliff, given that her phone landed 20 m away when she accidentally threw her phone with a velocity of 5 m/s is 78.4 m

To determine the height of the cliff, we must first obtain the time taken for her phone to reach the ground. This is obtained as follow:

s = ut

20 = 5 × t

Divide both sides by 5

t = 20 / 5

t = 4 s

Finally, we shall determine the height of the cliff. Details below:

h = ½gt²

h = ½ × 9.8 × 4²

h = 4.9 × 16

h = 78.4 m

Thus, the height of the cliff is 78.4 m

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You did look at solar activity on the heliophysics event registry website, and we found activity on the sun on the specified day.

Any natural occurrence in the upper atmosphere of the sun is referred to as a solar phenomenon. Solar flares, prominences and filaments, and coronal mass ejections are three different categories of solar phenomena.

The simplest way we can investigate how solar activity changes over time is to survey sunspots, which is also how we track the solar cycle. Sunspots are associated with the Sun's natural 11-year cycle, during which the planet's surface changes from calm to turbulent.

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The speed of the wave is determined as 18 m/s.

option D is the correct answer.

The speed of the wave is the rate of change of wave's displacement with time.

The speed of the wave is calculated by applying the formula relating speed, wavelength and frequency of the wave as shown below.

v = fλ

where;

The frequency of the wave is calculated as follows;

f = 1 / T

where;

The period of a wave is the time taken for the wave to complete one cycle.

In the picture given, 3 cycles of the wave = 0.5 s

1 cycle of the wave = ?

= 0.5 s / 3

= 0.16667 s

f = 1 / T

f = 1 / 0.16667

f = 6 Hz

The speed of the wave is calculated as follows;

v = fλ

v = 6 Hz  x  3 m

v = 18 m/s

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The Effective Spring Constant is [tex](\frac{k1k2}{k1 + k2} )[/tex] for a system of 2 springs with spring constant k1 and k2.

The term "spring constant" refers to the proportional constant k. It gauges the stiffness of the spring. A spring exerts a force F = -kx in the direction of its equilibrium position when it is stretched or compressed to a length that differs by an amount x from its equilibrium length.

Spring constants are available in plural (physics) a quality of a spring that is determined by the force acting on the spring to the displacement it produces.

K stands for the proportionality constant, commonly referred to as the "spring constant." In layman's words, stiffness and strength are shown by the k variable in Hooke's law (F = -kx). An item requires more force to be stretched to a specific length the greater the value of k.

Let the force actiong be F N

then , if k1 is the spring constant of spring 1

F = x1 * k1

or, x1 = F/k1.

Similarly for spring 2

x2 = F/k2

Now x1 + x2 = F (1/k1 + 1/k2)

or effective displacement

X= [tex]F(\frac{1}{k1} + \frac{1}{k2} )[/tex]

or, F = [tex]X * (\frac{k1k2}{k1 + k2} )[/tex]

So the Effective Spring Constant is [tex](\frac{k1k2}{k1 + k2} )[/tex].

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The velocity of vehicles after the collision is 15.82m/sec if car mass is 1.4 × 10³kg and truck mass is 2×10³kg

We know that we need to conserve the momentum of watermelon in a certain direction. Also,we know that initial momentum of watermelon is zero,it means that according to law of conservation of momentum final momentum should be zero.

We know that momentum =mass × velocity

So,initial momentum of car is =1.4 × 10³kg × 37km/hr

Similarly,,initial momentum of truck=2×10³kg × 35km/hr

Now,it is given that both vehicles lock together,so total mass of both vehicles is =1.4 × 10³kg +  2×10³kg=3.4 ×10³kg

Assume final velocity of both vehicle is v

So,following the law of conservation,we get

=>1.4 × 10³kg × 37 + 2×10³kg × 35 = 3.4 ×10³ ×v

=>51.8 ×10³ + 2×10³=3.4×10³ ×v

=>53.8 ×10³ kg-m/sec = 3.4×10³ ×v

=>v = 53.8/3.4

=>v=15.82m/sec

Hence,final velocity of both vehicle after collision is 15.82m/sec.

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The star Sirius is indeed brighter but our Sun appears to be brighter because it is closer to us.

The intrinsic luminosity of Sirius is exactly 25.4 times more than the sun but if we compare the distances of these stars, Sirius is 8.6 light years away from us and the Sun is just 8 light minutes away from us. This marks the obvious reason why our Sun appears more bright.

Even mathematically, it can be justified as the apparent brightness of any luminous object depends on the inverse square of the distance of that luminous object. Therefore the sun's light energy dominates our sky and we can't see any traces of Sirius from the earth.

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