Answer:
Explanation:
We shall apply conservation of mechanical energy .
initial kinetic energy = 1/2 m v²
= .5 x m x 12 x 12
= 72 m
This energy will be spent to store potential energy . if h be the height attained
potential energy = mgh , h is vertical height attined by block
= mg l sin20 where l is length up the inclined plane
for conservation of mechanical energy
initial kinetic energy = potential energy
72 m = mg l sin20
l = 72 / g sin20
= 21.5 m
deceleration on inclined plane = g sin20
= 3.35 m /s²
v = u - at
t = v - u / a
= (12 - 0) / 3.35
= 3.58 s
it will take the same time to come back . total time taken to reach original point = 2 x 3.58
= 7.16 s
When the child is moving, he/she has kinetic energy. For just a brief second before they move the other way, the child is not moving, but they have gravitational potential energy.
The child may need a push from time to time because friction with the air causes loss of energy.
Answer:
Sound waves that we can hear have much longer wavelengths than do light waves. As a result, the diffraction of sound waves around a corner is noticeable and we can hear the sound in the “shadow region,” but the diffraction of light waves around a corner is not noticeable.
Explanation:
i hope that helps :)...<3
Answer:
= 1000 hours
Explanation:
Earth's circumference is 10⁴ mile
speed of a sailboat is 10¹ mile/hour
distance = speed × time
10⁴ = 10¹ × t
t = 10⁴ / 10¹
t = 10³
= 1000 hours
A) because it is an element.
Explanation: usually when they say pure substance they mean pure element.
Hope this helped!! :)
