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3 years ago

D. What is the net force on the bowling ball rolling lane

Physics

1 answer:

3241004551 [841]3 years ago

3 0

Answer:

Friction

Explanation:

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Calculate the number of vacancies per cubic meter in iron at 850 °C. The energy for vacancy formation is 1.08 eV/atom. Furthermo

Fed [463]

Answer:

The number of vacancies per cubic meter is 1.18 X 10²⁴ m⁻³

Explanation:

$N_v = N*e[^{-\frac{Q_v}{KT}}] = \frac{N_A*\rho _F_e}{A_F_e}e[^-\frac{Q_v}{KT}}]$

where;

N $_A$ is the number of atoms in iron = 6.022 X 10²³ atoms/mol

ρFe is the density of iron = 7.65 g/cm3

AFe is the atomic weight of iron = 55.85 g/mol

Qv is the energy vacancy formation = 1.08 eV/atom

K is Boltzmann constant = 8.62 X 10⁻⁶ k⁻¹

T is the temperature = 850 °C = 1123 k

Substituting these values in the above equation, gives

$N_v = \frac{6.022 X 10^{23}*7.65}{55.85}e[^-\frac{1.08}{8.62 X10^{-5}*1123}}]\\\\N_v = 8.2486X10^{22}*e^{(-11.1567)}\\\\N_v = 8.2486X10^{22}*1.4279 X 10^{-5}\\\\N_v = 1.18 X 10^{18}cm^{-3} = 1.18 X 10^{24}m^{-3}$

Therefore, the number of vacancies per cubic meter is 1.18 X 10²⁴ m⁻³

3 0

4 years ago

A dockworker loading crates on a ship finds that a 20 kg crate, initially at rest on a horizontal surface, requires a 70 N horiz

frez [133]

The coefficient of static friction is 0.357 and the coefficient of kinetic friction is 0.265.

Explanation:

Coefficient of static friction is defined as the proportionality constant for the frictional force between the crate and floor for starting the motion of crate and normal force acting on the crate. As the normal force of the crate is equal to the influence of acceleration due to gravity acting on the mass of the crate, the frictional force for static friction coefficient will be the force applied to move the crate.

Thus, $Static friction force = Coefficient of static friction * Normal force\\\\$

Since, the static friction force is 70 N, the normal force is equal to $Mass * acceleration due to gravity = 20 * 9.8 = 196 N$

So normal force is 196 N and static force is 70 N, and the ratio of static friction force to the normal force will give the coefficient of static friction.

$Coefficient of static friction = \frac{Static friction force}{Normal force}\\ \\Coefficient of static friction = \frac{70}{196} = 0.357$

Similarly, the coefficient of kinetic friction can be determined from the ratio of kinetic friction force to normal force. Here the kinetic friction force will be equal to the force applied on the crate to keep it moving.

$Coefficient of kinetic friction = \frac{Kinetic friction force}{Normal force}\\ \\Coefficient of kinetic friction = \frac{52}{196} = 0.265$

Thus, the coefficient of static friction is 0.357 and the coefficient of kinetic friction is 0.265.

6 0

3 years ago

A parallel-plate capacitor with plates of area 360 cm2 is charged to a potential difference V and is then disconnected from the

Softa [21]

Answer:

$Q=3.9825\times 10^{-9} C$

Explanation:

We are given that a parallel- plate capacitor is charged to a potential difference V and then disconnected from the voltage source.

1 m =100 cm

Surface area =S= $\frac{360}{10000}=0.036 m^2$

$\Delta d=0.8 cm=0.008 m$

$\Delta V=100 V$

We have to find the charge Q on the positive plates of the capacitor.

V=Initial voltage between plates

d=Initial distance between plates

Initial Capacitance of capacitor

$C=\frac{\epsilon_0 S}{d}$

Capacitance of capacitor after moving plates

$C_1=\frac{\epsilon_0 S}{(d+\Delta d)}$

$V=\frac{Q}{C}$

Potential difference between plates after moving

$V=\frac{Q}{C_1}$

$V+\Delta V=\frac{Q}{C_1}$

$\frac{Qd}{\epsilon_0S}+100=\frac{Q(d+\Delta d)}{\epsilon_0S}$

$\frac{Q(d+\Delta d)}{\epsilon_0 S}-\frac{Qd}{\epsilon_0S}=100$

$\frac{Q\Delta d}{\epsilon_0 S}=100$

$\epsilon_0=8.85\times 10^{-12}$

$Q=\frac{100\times 8.85\times 10^{-12}\times 0.036}{0.008}$

$Q=3.9825\times 10^{-9} C$

Hence, the charge on positive plate of capacitor= $Q=3.9825\times 10^{-9} C$

6 0

4 years ago

James took two pea plants, placing one in a dark closet and the other on a sunny window sill. Both are located in air-conditione

aksik [14]

I think the correct answer from the choices listed above is option A. In this experiment, sunlight is an independent variable. It is the variable that cannot be changed James no matter what. Hope this answers the question. Have a nice day.

6 0

3 years ago

Read 2 more answers

Object A with a mass of 500 kilograms hits stationary object B with a mass of 920 kilograms. If the collision is elastic, what h

Vika [28.1K]

In elastic collision, both the kinetic energy and momentum are conserved. Conservation means that both the kinetic energy and momentum will have the same values before and after elastic collision.

<span>As the object A has low mass than object B. Hence upon collision, object B moves forward, while object A will move backward. So option "C" is correct. </span>

5 0

4 years ago