Answer:
Third Option
Explanation:
If we have a vector A = ax + by we know that by definition
cA = cax + cby
Where c is a constant.
In this case we have two vectors
You may notice that vector B has an opposite direction to vector A.
You may also notice that | Ax | is the double of | Bx | and | Ay | is double of |By |
That is to say
So the equation that relates to vectors A and B is:
.
You can verify this relationship by performing the operation
<span>If the swimmer is swimming perpendicular to the current, it will take her 66m / 0.42 m/s = 157.14 seconds to cross the river. At the same time, the current will be taking her downstream at a rate of 0.32 m/s. So, when she reaches the opposite bank, her total downstream distance traveled will have been 0.32*157.14 = 50.28 meters.</span>
On a part-time job, you are asked to bring a cylindrical iron rod of density 7800 kg/m3 , length 92.8 cm and diameter 2.05 cm from a storage room to a machinist, the weight of rod w is 23.41 N .
<h3>How is the weight calculated?</h3>
Given ,
density (d) = 7800 kg/m³
D = 2.05 cm = 0.0205 m
r = D/2 = 0.0205 / 2 =0.01025 m
h = 92.8 cm = 0.928 m
The weight is calculated by ,
W = m × g
But, to find mass (m)
m = d × V
The volume of the rod, because is cylindrical, is,
V = π × r² × h
∴ V = 3.14 × (0.01025)² × 0.928
∴ V = 3.14 × 1.051 × 10⁻⁴ × 0.928
∴ V = 3.0625 × 10⁻⁴
Now to calculate mass,
m = d × V
∴ m = 7800 × 3.0625 × 10⁻⁴
∴ m = 2.3887 Kg
Now, for calculating weight
W = m × g
∴ W = 2.3887 × 9.8
∴ W = 23.41 N
∴ The weight of the rod W assuming the free-fall acceleration is 23.41 N .
<h3>What is weight?</h3>
- The weight of an object is the force exerted on it by gravity.
- It is define weight as a vector quantity, the force of gravity acting on an object.
- Some define weight as a scalar quantity that is the magnitude of gravity.
Can learn more about weight calculation from brainly.com/question/15685221
#SPJ4
Answer:
If you try to lift up a weight in a swimming pool and then try to lift the same weight on the edge of the pool, it feels much lighter in the water.
This was supposed to have been first explained by the Greek scientist Archimedes. He said that the water gives an upward force or upthrust on any object in it.
You can weigh an object in air and then in water and actually work out the upthrust, it is the difference between the two readings. For this reason the upthrust is often called the loss in weight of the object.
Place the object in an electronic balance and measure its mass.
Place a measured amount of water in the cylinder.
Place the object in the cylinder so that it’s fully submerged.
Measure the new level of the liquid and subtract the original level. This is equal to the volume of the object.
Density = mass / volume.
