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2 years ago

If a crane worker lifts a crate with a mass of 250 kg from the ground to a

Physics

1 answer:

mina [271]2 years ago

7 0

The gravitational of a body is possessed by the body due to the virtue of its position.

The formula for gravitational potential energy is,

P.E = mgh joules

Substituting the values

196*9.8*250= 49k

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Nostrana [21]

Answer:

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Explanation:

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3 years ago

In a concave mirror, if an object is located between the center of curvature and the focal point, what is the best way to descri

alisha [4.7K]

Light rays travel parallel to each other, no image formed

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3 years ago

Read 2 more answers

Two loudspeakers in a 20c room emit 686 hz sound waves along the x-axis.a. if the speakers are in phase, what is the smallest di

jeyben [28]

<u>Answer :</u>

(a) d = 0.25 m

(b) d = 0.5 m

<u>Explanation :</u>

It is given that,

Frequency of sound waves, f = 686 Hz

Speed of sound wave at $20^0\ C$ is, v = 343 m/s

(1) Perfectly destructive interference occurs when the path difference is half integral multiple of wavelength i.e.

$d=\dfrac{\lambda}{2}$ ........(1)

Velocity of sound wave is given by :

$v=f\times \lambda$

$d=\dfrac{v}{2f}$

$d=\dfrac{343\ m/s}{2\times 686\ Hz}$

$d=0.25\ m$

Hence, when the speakers are in phase the smallest distance between the speakers for which the interference of the sound waves is perfectly destructive is 0.25 m.

(2) For constructive interference, the path difference is integral multiple of wavelengths i.e.

$d=n\lambda$ ( n = integers )

Let n = 1

So, $d=\dfrac{v}{f}$

$d=\dfrac{343\ m/s}{686\ Hz}$

$d=0.5\ m$

Hence, the smallest distance between the speakers for which the interference of the sound waves is maximum constructive is 0.5 m.

4 0

3 years ago

Read 2 more answers

A dentist’s drill starts from rest. After 4.28 s of constant angular acceleration it turns at a rate of 28940 rev/min. Find the

mylen [45]

Answer:

Angular acceleration, is $708.07\ rad/s^2$

Explanation:

Given that,

Initial speed of the drill, $\omega_i=0$

After 4.28 s of constant angular acceleration it turns at a rate of 28940 rev/min, final angular speed, $\omega_f=28940\ rev/min=3030.58\ rad/s$

We need to find the drill’s angular acceleration. It is given by the rate of change of angular velocity.

$\alpha =\dfrac{\omega_f}{t}\\\\\alpha =\dfrac{3030.58\ rad/s}{4.28\ s}\\\\\alpha =708.07\ rad/s^2$

So, the drill's angular acceleration is $708.07\ rad/s^2$ .

4 0

3 years ago

Heather and Matthew walk with an average velocity of 0.98 m/s eastward. If it takes them 34 min to walk to the store, what is th

TEA [102]

Answer:

D= 1999.2 m

Explanation:

Given that

Average velocity ,v= 0.98 m/s

time ,t= 34 min

We know that

1 min = 60 s

That is why

t= 34 x 60 =2040 s

We know that

Displacement = Average velocity x time

D= v t

Now by putting the values in the above equation

D= 0.98 x 2040 m

D= 1999.2 m (eastward)

The direction of the displacement will be towards eastward.

That is why the displacement will be 1999.2 m or we can say that 1.9992 km.

3 0

3 years ago