Someone help please !!?

This table lists the densities of four different substances.

cestrela7 [59]

Answer:

GREATER than 1 g/cm. 3, it will SINK in water. LESS than 1 g/cm3, it will FLOAT in water. If an object's density is: Density of Object > Density of Liquid.

Explanation:

3 0

4 years ago

A hollow sphere of radius 0.200 m, with rotational inertia I = 0.0484 kg·m2 about a line through its center of mass, rolls witho

d1i1m1o1n [39]

Answer:

Part a)

$KE_r = 8 J$

Part b)

v = 3.64 m/s

Part c)

$KE_f = 12.7 J$

Part d)

$v = 2.9 m/s$

Explanation:

As we know that moment of inertia of hollow sphere is given as

$I = \frac{2}{3}mR^2$

here we know that

$I = 0.0484 kg m^2$

R = 0.200 m

now we have

$0.0484 = \frac{2}{3}m(0.200)^2$

$m = 1.815 kg$

now we know that total Kinetic energy is given as

$KE = \frac{1}{2}mv^2 + \frac{1}{2}I\omega^2$

$KE = \frac{1}{2}mv^2 + \frac{1}{2}I(\frac{v}{R})^2$

$20 = \frac{1}{2}(1.815)v^2 + \frac{1}{2}(0.0484)(\frac{v}{0.200})^2$

$20 = 1.5125 v^2$

$v = 3.64 m/s$

Part a)

Now initial rotational kinetic energy is given as

$KE_r = \frac{1}{2}I(\frac{v}{R})^2$

$KE_r = \frac{1}{2}(0.0484)(\frac{3.64}{0.200})^2$

$KE_r = 8 J$

Part b)

speed of the sphere is given as

v = 3.64 m/s

Part c)

By energy conservation of the rolling sphere we can say

$mgh = (KE_i) - KE_f$

$1.815(9.8)(0.900sin27.1) = 20- KE_f$

$7.30 = 20 - KE_f$

$KE_f = 12.7 J$

Part d)

Now we know that

$\frac{1}{2}mv^2 + \frac{1}{2}I(\frac{v}{r})^2 = 12.7$

$\frac{1}{2}(1.815) v^2 + \frac{1}{2}(0.0484)(\frac{v}{0.200})^2 = 12.7$

$1.5125 v^2 = 12.7$

$v = 2.9 m/s$

8 0

4 years ago

Mechanical energy that has been "lost" to friction has actually been

umka21 [38]

The answer to the question is true

5 0

4 years ago

Read 2 more answers

Calculate the freezing point of a solution of 40.0 g methyl salicylate, c7h6o2, dissolved in 800. g of benzene, c6h6. and the fr

Cloud [144]

From the problem statement, we are given a solution thus the solute in the solution would have an effect on some of the properties of the whole system. These properties are called the colligative properties. To calculate the freezing point of the solution, we use the freezing point depression equation which is expressed as follows:

ΔTf = kf(m)i

where ΔTf represents the freezing point depression, kf is a constant which 4.90 C/m for benzene, i is the vant hoff factor which is 1 for the given solute since it does not dissociate into ions and m is the molality of the solution. We calculate as follows:

ΔTf = kf(m)i
ΔTf = 4.90 (40.00 / .800 (122.13)) (1)
ΔTf = 2.01 C

ΔTf = Tf - Tfs
Tfs = 5.5 - 2.01
Tfs = 3.49 C

The correct answer would be the first option.

3 0

3 years ago

An electron with an initial speed of 660,000 m/s is brought to rest by an electric field. What was the initial kinetic energy of

GREYUIT [131]

Answer:

Kinetic energy of the electron $E_k=1.23\ eV$