Answer:
When the bag of apples are on the floor, the force of gravity is equal to the force applied in the upward direction.
But when the girl picks up the bag of apples, she applies a force on the bag of apples in the upward direction greater than that of the gravitational force.
Explanation:
Gravitational force for an object is always constant at a specific point. When an object is in the state of rest, there is an equal force opposite to the direction of Gravitational Force.
Now, to lift an object upwards, an external force must be applied that is greater than the force of gravitation.
So, when the girl picks up the bag of apples,
Gravitational Force < Force applied by the girl to lift the bag.
Answer:
The coil radius of other generator is 5.15 cm
Explanation:
Consider the equation for induced emf in a generator coil:
EMF = NBAω Sin(ωt)
where,
N = No. of turns in coil
B = magnetic field
A = Cross-sectional area of coil = π r²
ω = angular velocity
t = time
It is given that for both the coils magnetic field, no. of turn and frequency is same. Since, the frequency is same, therefore, the angular velocity, will also be same. As, ω = 2πft.
Therefore, EMF for both coils or generators will be:
EMF₁ = NBπr₁²ω Sin(ωt)
EMF₂ = NBπr₂²ω Sin(ωt)
dividing both the equations:
EMF₁/EMF₂ = (r₁/r₂)²
r₂ = r₁ √(EMF₂/EMF₁)
where,
EMF₁ = 1.8 V
EMF₂ = 3.9 V
r₁ = 3.5 cm
r₂ = ?
Therefore,
r₂ = (3.5 cm)√(3.9 V/1.8 V)
<u>r₂ = 5.15 cm</u>
Answer & Explanation:
Scientists call them all electromagnetic radiation. The waves of energy are called electromagnetic (EM) because they have oscillating electric and magnetic fields. Scientists classify them by their frequency or wavelength, going from high to low frequency (short to long wavelength).
If by chance you mean any wave, the wave with the shortest wavelength/highest frequency is gamma rays.
