Metals are not brittle so it can’t be the first one or the third one, both metalloids and metals are shiny so it can’t be the second one. Therefore, it would be the last one because both metalloids and metals are shiny and both are solids at room temperature because it is not a high enough melting point.
ANSWER: Both are shiny and are solid at room temperature.
Explanation :
The full form of laser is Light Amplification by Stimulated Emission of Radiation. It has particles of very high energy. It points in one direction.
Greg is giving a slide show presentation to a large audience. It is very important to make the presentation informative. By using a laser, we can focus on the important part of the presentation. So that we can highlight the important points.
The motion of the light is a uniform motion with constant speed
, therefore we can use the basic relationship between speed, space and time:
(1)
where S is the distance covered and t is the time taken. The light takes t=1.3 s to travel from the moon to Earth, therefore by rearranging eq.(1) we can find the distance between the Moon and the Earth:
<span>
E = mc^2 = 8.152*10^-30 *(3.00 *10^8)^2 = 7.336 *10^-13 J. </span>
Answer:
a ) = 381.48 J
b )= 84.25 cm
Explanation:
Kinetic energy of the runner
= 1/2 m v²
= .5 x 66 x 3.4²
= 381.48 J
The final kinetic energy of the runner is zero .
Loss of mechanical energy
= 381.48 J
This loss in mechanical energy is due to action of frictional force .
b )
Let s be the distance of slide
deceleration due to frictional force
= μmg/m
.7 x 66 x 9.8 / 66
a = - 6.86 m s⁻¹
v² = u² - 2 a s
0 = 3.4² - 2x6.86 s
s = 3.4² / 2x6.86
= .8425 m
84.25 cm
