In the properties of matter case study lab how did the criminals make the coins look gold

If a ball is dropped from rest and falls 8 m to the ground, what is the speed just before it

Natalija [7]

Answer:

12.5m/s

Explanation:

(Assuming the question was asking for the speed just before it hit the ground)

We can use the first key equation of accelerated motion

Vf^2 = Vi^2+2aΔd

Vf^2 = 0 + 2(9.8)(8) (plugged in values, initial velocity is 0 since the ball was at rest)

Vf^2 = 156.8

Vf = 12.5 (squared both sides)

4 0

2 years ago

What kind of motion happens at the atomic/molecular level of ALL solids, liquids and gases?

gayaneshka [121]

The answer is kinetic motion

6 0

4 years ago

A hammer has a mass of 1 kg. What is its weight (i) on Earth (ii) on the

solong [7]

Given mass= 1kg

Weight on earth = mg(gravity of earth) = 9.8N

weight on moon = mg(gravity of moon)= 1.62N

weight on outer space mg(gravity outer space = 0) = 0N

4 0

3 years ago

We can reasonably model a 90-W incandescent lightbulb as a sphere 5.7 cm in diameter. Typically, only about 5% of the energy goe

o-na [289]

Answer:

See answer

Explanation:

Given quantities:

$\eta = 0.05\\ W=90[W]\\r=0.0285[m]$

where $\eta$ is the efficiency of the lightbulb (visible light is 5% of the total power), $W$ is the total power of the lightbulb, r is the radius of the lightbulb in meters.

Intensity is power divided by area:

$I =\frac{P}{A}$

a) Now the effective power is $\eta*W$ , therefore:

$I =\frac{\eta*W}{\pi r^2}=\frac{0.05*90}{4\pi (0.0285)^2}=440.87[W/m^2]$

b) Now the intensity is the average poynting vector is related to the magnitudes of the maximum electric field and magnetic field amplitudes, following:

$S_{average}= \frac{EB}{2\mu_{0}}[W/m]$

now $E$ and $B$ are related:

$E=cB\\ B=\frac{E}{c}$ and $c=\frac{1}{\sqrt{\epsilon_{0} \mu_{0}}}$

replace in $S_{average}$

$S_{average}=I= \frac{c \epsilon_{0}E^2}{2}[W/m]$

we replace the values and we get:

$E= \sqrt{\frac{2I}{\epsilon_{0}c}}$

$E = \sqrt{\frac{2(440.8)}{8.85*10^{-12}3*10^8}}=576.24[V/m]$

therefore

$B=\frac{E}{c}=\frac{576.24}{3*10^{8}}=1.92*10^{-6}[T]$

8 0

3 years ago

What is the momentum of a bicycle with a mass of 18 kg traveling at 20 m/s?

iogann1982 [59]

Answer:360 kg m/s

Explanation:Momentum refers to an object's quantity of motion.

Formula for Momentum: p=mv

p = refers to the momentum

m = refers to the object's mass (this is represented by the unit kg or kilogram)

v = this refers to the object's velocity (this is represented by the unit m/s or meter per second)

So, given that the bike has a mass of 18 kg and is traveling at 20 m/s, then you can already get the momentum by multiplying both of these values.

p = the bike's momentum (what is being asked here)

m = 18 kg

v = 20 m/s

Thus, p = 18kg × 20 m/s = 360 kg m/s

The bike's momentum is 360 kg m/s.

Brainlist please

6 0

3 years ago