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2 years ago

An older fire alarm has a wax block keeping the circuit open. When the heat from a fire melts the block, the

Physics

1 answer:

Olegator [25]2 years ago

8 0

The heat from the fire melting the wax helps close the circuit.

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If you push an elephant and mouse with the same force, which would accelerate the least, why?

Nataly_w [17]

Ofcoure the elephante as the elephant has more weight

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3 years ago

Read 2 more answers

El salto con garrocha es practicado por:

Ulleksa [173]

D. Solo a y b
De nada

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3 years ago

PLEASE HELP!! WORTH A TOTAL OF 100 POINTS!!

Serjik [45]

The last equation gives you the tension in the string on the right:

$T_2 = 2Mg - 2Ma = 2M (g-a) = \boxed{33.2 \, \mathrm N}$

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2 years ago

At what angle should the axes of two polaroids be placed so as to reduce the intensity of the incident unpolarized light to 13.

prohojiy [21]

Answer:

θ = 66.90°

Explanation:

we know that

$I= \frac{I_0}{2}cos^2\theta$

I= intensity of polarized light =1

I_o= intensity of unpolarized light = 13

putting vales we get

$1= \frac{13}{2}cos^2\theta$

⇒ $\theta=cos^{-1} \sqrt{\frac{1}{6.5} }$

therefore θ = 66.90°

5 0

3 years ago

You stand on a bridge above a river and drop a rock into the water below from a height of 25 m. (Assume no air resistance)

Ilia_Sergeevich [38]

PART a)

here when stone is dropped there is only gravitational force on it

so its acceleration is only due to gravity

so we will have

$a = g = 9.8 m/s^2$

Part b)

Now from kinematics equation we will have

$y = v_i t + \frac{1}{2} at^2$

now we have

y = 25 m

so from above equation

$25 = 0 + \frac{1}{2}(9.8 )t^2$

$t = 2.26 s$

Part c)

If we throw the rock horizontally by speed 20 m/s

then in this case there is no change in the vertical velocity

so it will take same time to reach the water surface as it took initially

So t = 2.26 s

Part D)

Initial speed = 20 m/s

angle of projection = 65 degree

now we have

$v_x = vcos\theta$

$v_x = 20 cos65 = 8.45 m/s$

$v_y = vsin\theta$

$v_y = 20 sin65 = 18.13 m/s$

PART E)

when stone will reach to maximum height then we know that its final speed in y direction becomes zero

so here we can use kinematics in Y direction

$v_f - v_y = at$

$0 - 18.13 = (-9.8) t$

$t = 1.85 s$

so it will take 1.85 s to reach the top

5 0

3 years ago