Answer:
Da=(1/4)Db
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²
When s = Da, t = t

When s = Db, t = 2t

Dividing the two equations

Hence, Da=(1/4)Db
D. Atoms.
Explanation:
All the matter is made of elementary particles called "atoms".
Further, an atom is made of electrons, protons and neutrons. The electrons & protons are again made of the fundamental sub-particles, electrons (leptons) and the protons(quarks).
The classification of particles is shown in the figure attached
Answer:
0.68 m
Explanation:
α = dL / L1*(dT)
dL = L1(dT) * α
Initial length, L1 = 100
Chang in Length =dL
α linear expansivity ; dL = change in length ; dT = change in temperature ; L1 = initial length
α of iron rod = 1.13 * 10^-5 k
dL = 100(40 - 10) * 1.13 * 10^-5
dL = 100(30) * 1.13 * 10^-5
dL = 3000 * 1.13 * 10^-5
dL = 3390 * 10^-5
dL = 0.0339 m
Error :
Distance measured = 2km = (2 * 1000) = 2000m
[Distance measured / (initial length + change in length)] × change in length
Error = (2000 / (100 + 0.0339)) * 0.0339
Error = (2000 / 100.0339) * 0.0339
Error = 19.993222 * 0.0339
Error = 0.6777702
Error = 0.68 m
Answer:
The distance the ball moves up the incline before reversing its direction is 3.2653 m.
The total time required for the ball to return to the child’s hand is 3.2654 s.
Explanation:
When the girl is moving up:
The final velocity (v) = 0 m/s
Initial velocity (u) = 4 m/s
a = -0.25g = -0.25*9.8 = -2.45 m/s². (Negative because it is in opposite of the velocity and also it deaccelerates while going up).
Let time be t to reach the top.
Using
v = u + a×t
0 = 4 - 2.45*t
t = 1.6327 s
Since, this is the same time the ball will come back. So,
<u>Total time to go and come back = 2* 1.6327 = 3.2654 s
</u>
To find the distance, using:
v² = u² + 2×a×s
0² = 4² + 2×(-2.45)×s
s = 3.2653 m
<u>Thus, the distance the ball moves up the incline before reversing its direction is 3.2653 m.</u>