Answer:
The velocity is 
Explanation:
From the question we are told that
The first distance is 
The first speed is 
The second distance is 
The second speed is 
Generally the time taken for first distance is
The time taken for second distance is
The total time is mathematically represented as
=> 
=> 
Generally the constant velocity that would let her finish at the same time is mathematically represented as
=> 
=>
Answer: Weight = 98.1N
Explanation:
Density of water = 1000 kg/m^3
Given that the Plastic foam is about 0.10 times as dense as water. That is,
Density of plastic foam = 0.1 × 1000 = 100kg/m^3
The volume V = 1 ×1×0.1 = 0.1 m^3
Density is the ratio of mass to volume
Density = mass/volume
Let us substitute for density and volume to get mass.
100 = M/0.1
Make M the subject of formula
M = 100 × 0.1 = 10 kg
Weight = mg
Where g = 9.81 m/s
Substitute the M and g into the formula
Weight = 10 × 9.81 = 98.1 N
Therefore, the weight of the brick is 98.1 N
Answer:
Explanation:
Given:
- initial gauge pressure in the container,
- atmospheric pressure at sea level,
- initial volume,
- maximum pressure difference bearable by the container,
- density of the air,
- density of sea water,
<u>The relation between the change in pressure with height is given as:</u>
where:
dz = height in the atmosphere
= standard value of gravity
<em>Now putting the respective values:</em>
Is the maximum height above the ground that the container can be lifted before bursting. (<em>Since the density of air and the density of sea water are assumed to be constant.</em>)
Answer:
Absolute error=0.006
Percentage Relative error=0.6
Explanation:
The resistors have resistance of 24 ohm and 8 ohm.
The change in resistance is 0.5 and 0.3 ohm respectively.
Relative error for parallel combination of resistors is
= dR/R²
= dR1/R1² + dR2/R2²
= 0.5/(24)² + 0.3/(8)²
= 0.5/ 24*24 + 0.3/ 64
= 0.5/576+0.3/ 64
= 32 + 172.8/ 36,864
=204.8/ 36,864=0.0055
=0.006
Percentage error =Relative error *100
= 0.006* 100 = 0.6
Answer:
E/4
Explanation:
The formula for electric field of a very large (essentially infinitely large) plane of charge is given by:
E = σ/(2ε₀)
Where;
E is the electric field
σ is the surface charge density
ε₀ is the electric constant.
Formula to calculate σ is;
σ = Q/A
Where;
Q is the total charge of the sheet
A is the sheet's area.
We are told the elastic sheet is a square with a side length as d, thus ;
A = d²
So;
σ = Q/d²
Putting Q/d² for σ in the electric field equation to obtain;
E = Q/(2ε₀d²)
Now, we can see that E is inversely proportional to the square of d i.e.
E ∝ 1/d²
The electric field at P has some magnitude E. We now double the side length of the sheet to 2L while keeping the same amount of charge Q distributed over the sheet.
From the relationship of E with d, the magnitude of electric field at P will now have a quarter of its original magnitude which is;
E_new = E/4
