Answer:
(A) 60 J
Explanation:
At state 1
KE₁=100 J
At state 2
KE₂ = 0
U₂=80 J
Given that surface is rough so friction force will act in opposite to the direction of motion
Lets take work done by friction = Wfr
From work power energy
Work done by all forces = Change in kinetic energy
Wfr + U₂=ΔKE
Wfr+80 = 100
Wfr= 20 J
Now when book slides from top position then
Wfr+ U = KEf - KEi
-20 + 80 = KEf-0
KEf= 60 J
(A) 60 J
In order to find the solid, you would want the object in which sound travels the fastest
In this case, since in object C, the speed of sound is the fastest, it is the most likely to be a solid
So object C is most likely to be a solid
Answer:
Planet Y
Rx = 1.587 Ry
Explanation:
Tx = 290 days
Ty = 145 days
Let the semi major axis of planet X is Rx and of plant Y is Ry.
According to the Kepler's third law of planetary motion




Rx = 1.587 Ry
So, planet Y is closest to star.
Answer:
- أكثر أنواع التربة خصوبة التربة
- الحمراء .
.
ج- السوداء
I’m not sure what variables you are given, but since work = force x distance, and force = mass x acceleration, you could use work = mass x acceleration x distance