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4 years ago

A 40kg rock is perched atop a cliff that is 50 m high. What is it’s potential energy?

1 answer:

4 0

Potential energy, is energy due to its position.

Given: Mass m = 40 Kg; Height h = 50 m

Required: Potential energy P.E = ?

Formula: P.E = mgh P.E = (40 Kg)(9.8 m/s²)(50 m)

P.E = 19,600 J

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A block pushed along the floor with velocity v0xv0x slides a distance dd after the pushing force is removed. If the mass of the

Volgvan

Answer:

There is no change in distance

Explanation:

Given that block slides a distance dd with initial velocity $v_{ox}$ $v_{ox}$

Work energy theorem states that Work done W is the difference between final kinetic energy $KE_{f}$ and initial kinetic energy $KE_{i}$

W = $KE_{f}$ - $KE_{i}$ ...........(equation 1)

In the given problem, the work is done by frictional force

Hence the work done is given by

$W_{Friction}$ = - $F_{Friction}$ x dd

$F_{Friction}$ is negative since it is resistive force and dd is the distance

$W_{Friction}$ = - μ mg X dd

where μ is coefficient of friction.

Also we know that Kinetic energy KE = $\frac{1}{2}$ $mv^{2}$

$KE_{f}$ = 0 since final velocity is zero

$KE_{i}$ = $\frac{1}{2}$ $m(v_{ox} v_{ox}) ^{2}$

Substituting the corresponding values equation 1 becomes

-μ mg x dd = 0 - $\frac{1}{2}$ $m(v_{ox} v_{ox}) ^{2}$

dd= $\frac{(v_{ox}v_{ox} )^{2} }{2g}$ x (1/μ) ........... (equation 2)

To find distance when mass of block is doubled and initial velocity is not changed:

Equation 2 shows that the distance dd is independent of mass, therefore there is no change in distance.

5 0

3 years ago

If I was born in 1998 how old will I be

brilliants [131]

Answer:

If your birthday was celebrated already then you would be 23, but if your birthday isn't celebrated then you would be 22

Explanation:

6 0

3 years ago

A barcode scanner emits a red light with frequency of 4.62x1014 s –1 . What is the wavelength of this light in nm?

NemiM [27]

Answer:

λ = 649 nm

Explanation:

given,

frequency,f = 4.62 x 10¹⁴ Hz

speed of light,c = 3 x 10⁸ m/s

we know,

c = f λ

$\lambda=\dfrac{c}{f}$

$\lambda=\dfrac{3\times 10^8}{4.62\times 10^{14}}$

λ = 6.4935 x 10⁻⁷ m

λ = 649 x 10⁻⁹ m

λ = 649 nm

the wavelength of this light is equal to 649 nm

4 0

3 years ago

A 190 g air-track glider is attached to a spring. The glider is pushed in 9.20 cm and released. A student with a stopwatch finds

Sholpan [36]

Answer:

$k = 12.136\,\frac{N}{m}$

Explanation:

The angular frequency of the system is:

$\omega = \sqrt{\frac{k}{m} }$

The frequency is:

$f = \frac{14\,osc}{11\,s}$

$f = 1.272\,hz$

The angular frequency is:

$\omega = 2\pi\cdot (1.272\,hz)$

$\omega = 7.992\,\frac{rad}{s}$

The spring constant is:

$k = \left(7.992\,\frac{rad}{s} \right)^{2}\cdot (0.190\,kg)$

$k = 12.136\,\frac{N}{m}$

6 0

3 years ago

Please Help lol. <br> just trying to get up the character count lol

9966 [12]

Answer:

8612

Explanation:

7 0

3 years ago