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A 25.0 kg child slides down a long slide in a playground. She starts from rest at a height h1 of 21.00 m. When she is partway do

____ [38]

Answer:

The mechanical energy lost due to friction is 2,424.5 J

Explanation:

Given;

mass of the child, m = 25 kg

intial velocity of the child, u = 0

final velocity of the child, v = 7.8 m/s

initial position of the child, h₁ = 21 m

final position of the child, h₂ = 8 m

Let the energy lost due to heat = ΔE

ΔE + ΔK.E + ΔP.E = 0

ΔE + ¹/₂m(v² - u²) + mg(h₂ - h₁) = 0

ΔE + ¹/₂ x 25(7.8² - 0) + 25 x 9.8(8 - 21) = 0

ΔE + 760.5 J - 3185 J =

ΔE - 2,424.5 J = 0

ΔE = 2,424.5 J

Therefore, the mechanical energy lost due to friction is 2,424.5 J

4 0

3 years ago

Four forces act at a point in the image above. calculate the resultant.

levacccp [35]

Answer:

50° and 60°

Explanation:

hope this help

3 0

3 years ago

Maria is filling a bucket of water from a faucet. After she turns it on, she sees that the cross-sectional area of the water str

GenaCL600 [577]

Answer:

t = 47.62 sec

Explanation:

Given data;

$A_1 = 4.62 \times 10^4 m^2$

$A_2 = 2.52 \times 10^4 m^2$

h = 2.50 cm

volume 10 L

from

$A_1 v_1 = A_2 v_2$

$4.62 \times 10^4 v_1 = 2.52 \times 10^4 v_2$

$4.62 v_1 = 2.52 v_2$ ......1

from bernoulli eq

$P_1 + \frac{1}{2} \rho v_1^2 + \rho g h = P_2 + \frac{1}{2} \rho v_2^2$

$P_1 =P_2 = P_{atm}$

$v_2^2 = v_1^2 +2gh$ ... 2

from 1 and 2 equation

$v_1 = 0.46 m/s$

volume flow rate is

$Q = A_1 \times v_1 = 4.62 \times 10^[-4} v_1 = 2.1 \times 10^{-4} m^3/s$

$t = \frac{v}{Q}$

$t =\frac{10\times 10^{-3}}{2.1 \times 10^{-4}} = 47.62 s$

3 0

3 years ago

Read 2 more answers

A sprinter has a mass of 80kg and a kinetic energy of 4000 j. What is the sprinter's speed

JulijaS [17]

The formula of the kinetic energy is KE = 0.5*m*v^2.
Given m = 80 kg and KE = 4000 J,
4000 = 0.5*80*v^2
v^2 = 100
v = 10 m/s

4 0

3 years ago

I need the answers to these questions

dimulka [17.4K]

The guy above looks correct

8 0

3 years ago