Answer:
Explanation:
Let A and B be two points located in a uniform electric field, A being a distance d from B in the direction of the field. The work that an external force must do to bring a unit positive charge q from the reference point to the point considered against the electric force at constant speed, mathematically is expressed by:
Therefore, isolating 
and replacing the data provided:
Answer:
They are caused by outward fluctuations of the sun's magnetic field.
They tend to occur during active periods of the solar cycle.
Explanation:
While sun spots will appear darker than the surrounding surface, flares will tend to appear brighter. CME's are associated with massive flares.
Answer:
The force is -1620.73 N.
Explanation:
Given that,
Mass of car = 1000 kg
Velocity = 1 m/s
Distance = 2 m
Angle = 30°
We need to calculate the force
Using formula of work done
Put the value into the formula
Hence, The force is -1620.73 N.
Answer:
1.635×10^-3m
Explanation:
Young modulus is the ratio of the tensile stress of a material to its tensile strain.
Young modulus = Tensile stress/tensile strain
Tensile stress = Force/Area
Given force = 130N
Area = Πr² = Π×(1.55×10^-3)²
Area = 4.87×10^-6m²
Tensile stress = 130/4.87×10^-6 = 8.39×10^7N/m²
Tensile strain = extension/original length
Tensile strain = e/3.9
Substituting in the young modulus formula given young modulus to be 2×10¹¹N/m²
2×10¹¹N/m² = 8.39×10^7/{e/3.9)}
2×10¹¹ = (8.39×10^7×3.9)/e
2×10¹¹e = 3.27×10^8
e = 3.27×10^8/2×10¹¹
e = 1.635×10^-3m
The stretch of the steel wire will be
1.635×10^-3m
