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3 years ago

A 75kg man climbs the stairs to the fifth floor of a building. A total hieght of 16m. His potential energy has increased by

Physics

1 answer:

yKpoI14uk [10]3 years ago

8 0

Answer:

11760 joules

Explanation:

Given

Mass (m) = 75kg

Height (h) = 16m

Required

Determine the increment in potential energy (PE)

This is calculated as thus:

PE = mgh

Where g = 9.8m/s²

Substitute values for m, g and h.

P.E = 75 * 9.8 * 16

P.E = 11760 joules

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You mines 150-250=100 Celsius

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3 years ago

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Kenny and Candy decided to sit on a see-saw while visiting a local play park. Candy, of mass

pochemuha

Answer:

(i) 208 cm from the pivot

(ii) Move further from the pivot

Explanation:

(i) Sum of the moments about the pivot of the seesaw is zero.

∑τ = Iα

(50 kg) (10 N/kg) (2.5 m) + (60 kg) (10 N/kg) x = 0

1250 Nm + 600 N x = 0

x = -2.08 m

Kenny should sit 208 cm on the other side of the pivot.

(ii) To increase the torque, Kenny should move away from the pivot.

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4 years ago

I was having trouble with this problem, and problems like it: A 3.2 kg pelican, with a 1.73 kg fish in its mouth, is flying 1.52

Oduvanchick [21]

Answer:

28.1 m/s

Explanation:

$u_x$ = Initial velocity of the fish = 1.52 m/s

y = Height of the bird = 40 m

$a_y$ = Acceleration in y axis = $9.81\ \text{m/s}^2$

$u_y$ = Initial velocity in y axis = 0

$y=u_yt+\dfrac{1}{2}a_yt^2\\\Rightarrow 40=0+\dfrac{1}{2}\times 9.81t^2\\\Rightarrow t=\sqrt{\dfrac{40\times 2}{9.81}}\\\Rightarrow t=2.86\ \text{s}$

$v_y=u_y+a_yt\\\Rightarrow v_y=0+9.81\times 2.86\\\Rightarrow v_y=28.057\ \text{m/s}$

The final velocity in x direction will remain the same as the initial velocity as there is no acceleration in the x direction $u_x=v_x=1.52\ \text{m/s}$

Resultant velocity is given by

$v=\sqrt{v_x^2+v_y^2}\\\Rightarrow v=\sqrt{1.52^2+28.057^2}\\\Rightarrow v=28.1\ \text{m/s}$

The fish is moving at a velocity of 28.1 m/s when it hits the water.

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3 years ago

A crate weighing 1000 Newton's needs to be lifted at a constant speed from the ground to a loading dock 1.5 meters high in 5.0 s

miskamm [114]

Answer:

the Power required is 300 W

Explanation:

We know that the definition of work is given by the following expresion:

$W=F*d$

the distance is 1.5 meters and the Force is equal to 1000 N.

Replacing this values in the work expresion

$w= 1000 *1.5 = 1500 J$

And the power is equal to the amount of work done in a given time, therefore we have:

$Power = \frac{work}{time} \\$

Time in seconds

$Power = 1500/5\\\\Power = 300 watts$

3 0

3 years ago

Wave 1 displaces according the function f(θ)= 2sin θ+1. Wave 2 displaces according to the function f(θ)= 3sin θ+.5. At what angl

r-ruslan [8.4K]

Answer:

θ = 30⁰

Explanation:

We have been given two wave displacement equations,

$y_{1} =2sin\theta +1$ ........(1)

$y_{2}=3sin\theta +0.5$ ........(2)

The waves will have same displacements when $y_{1}=y_{2}=y$ (say)

Therefore, operating (2) - (1), we get,

$sin\theta - 0.5=0$

or, $\theta = sin^{-1}(0.5)=30^{o}$ (since, sin 30⁰ = 0.5)

We can check the answer by putting $\theta=30^{o}$ in equations (1) and (2),

$y_{1}=2sin30^{o}+1=2\times0.5 + 1= 2$

$y_{2}=3sin30^{o}+0.5=3\times0.5+0.5=1.5+0.5=2$

6 0

3 years ago

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