The atomic mass of this question is 10.811
Answer:
The speed of the block when it has returned to the bottom of the ramp is 6.56 m/s.
Explanation:
Given;
mass of block, m = 4 kg
coefficient of kinetic friction, μk = 0.25
angle of inclination, θ = 30°
initial speed of the block, u = 5 m/s
From Newton's second law of motion;
F = ma
a = F/m
Net horizontal force;
∑F = mgsinθ + μkmgcosθ

At the top of the ramp, energy is conserved;
Kinetic energy = potential energy
¹/₂mv² = mgh
¹/₂ v² = gh
¹/₂ x 5² = 9.8h
12.5 = 9.8h
h = 12.5/9.8
h = 1.28 m
Height of the ramp is 1.28 m
Now, calculate the speed of the block (in m/s) when it has returned to the bottom of the ramp;
v² = u² + 2ah
v² = 5² + 2 x 7.022 x 1.28
v² = 25 + 17.976
v² = 42.976
v = √42.976
v = 6.56 m/s
Therefore, the speed of the block when it has returned to the bottom of the ramp is 6.56 m/s.
Answer:
Explanation:
A and B are in series , Total resistance = Ra + Rb
This resistance is in parallel with single resistor C
Equivalent resistance Re = Rc x ( Ra + Rb ) / [Rc + ( Ra + Rb )]
Now this combination is in series in single resistance D .
Total resistance = Rd + Re
= Rd + { Rc x ( Ra + Rb ) / [Rc + ( Ra + Rb )] }
Answer:
1. A solid can diffuse into a liquid, but a solid cannot diffuse into another solid.
3. A liquid can diffuse into another liquid.
4. A gas can diffuse into another gas.
Explanation:
When an object is in liquid or gas form, they can easily move and spread. This is because the molecules are packed loosely. Since they can move freely, diffusion on and into gas/liquid can be easily achieved.
Solid form can diffuse into liquid too. Seawater is mostly made of water and solid salt. But diffusing a solid into a solid is not possible since the molecule is tightly packed and barely moves. The diffusion might be happening, but at a really slow rate that we can assume it is not.