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3 years ago

Anyone who is willing to help me do some 8th grade science questionsNO LINKS

Physics

1 answer:

NISA [10]3 years ago

3 0

Answer:

what are they ill have a look

Explanation:

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Problem 24.3 The assembly is made from a steel hemisphere, rho st = 7. 80 Mg/m3 , and an aluminum cylinder, rho al = 2. 70 Mg/m3

AlladinOne [14]

Answer:

0.12 m

Explanation:

The mass of the steel hemisphere is:

$m_h=\rho_s\times \frac{2}{3}\pi r^2\\m_h = 7.8\times 10^3 \times \frac{2}{3}\pi (0.16)^2\\m_h=66.9 kg$

Mass of the aluminium cylinder is:

$m_c=\rho_a\times \pi r^2 h\\m_c=2.7\times 10^3 \times \pi (0.08)^2(0.18) \\m_c =9.7 kg$

mass center of steel hemisphere from the bottom:

$z_1=r-3r/8\\z_1=0.16-(3\times 0.16/8) =0.1 m$

mass center of aluminium cylinder from the bottom:

$z_2=r+h/2 \\z_2=0.16+0.18/2=0.25 m$

center of mass is

$Z=\frac{m_hz_1+z_2m_c}{m_s+m_c}\\Z=\frac{66.9\times 0.1+9.76\times 0.25}{66.9+9.76} = 0.12 m$

3 0

3 years ago

A 16.0 kg sled is being pulled along the horizontal snow-covered ground by a horizontal force of 25.0 N. Starting from rest, the

Fudgin [204]

Answer:

$\mu_k = 0.15$

Explanation:

according to the kinematic equation

$v^{2} - u^{2} = 2aS$

Where

u is initial velocity = 0 m/s

a = acceleration

S is distance = 8.00 m

final velocity = 1.0 m/s

$a = \frac {v^{2}}{2S}$

$a = \frac {1{2}}{2*8.6}$

a = 0.058 m/s^2

from newton second law

Net force = ma

$f_{net} = ma$

F - f = ma

2 $5 - \mu_kN = ma$

$25 - \mu_kmg = ma$

$\frac {25 - ma}{mg} =\mu_k$

$\frac {25 - 16*0.058}{16*9.81} = 0.15$

$\mu_k = 0.15$

4 0

3 years ago

An objest with the mass of 2 kg is accelerated at 4 m/s2. the net force acting on the object is

poizon [28]

From Newton’s 2nd law of motion
F=ma
= 2*4
=8N

8N should be the answer

5 0

3 years ago

What will be the time period of simple pendulum at the center of earth

Furkat [3]

Answer:

As g=0 at the centre of earth the time period becomes infinite as T=2pi/underoot g. At center of earth, r = 0 & hence g = 0. Time period of a simple pendulum is T = 2π sqrt (1/g).

Explanation:

7 0

3 years ago

A particle begins to move with uniform acceleration. If in the first second it travels 3m

nataly862011 [7]

Answer:6m

Explanation:

8 0

3 years ago