A battery is replaced with one of lower emf. State and explain how the resistance of the lamps would have to change in order to
1 answer:
The brightness of the lamp is proportional to the current flowing through the lamp: the larger the current, the brighter the lamp.
The current flowing through the lamp is given by Ohm's law:
where
V is the potential difference across the lamp, which is equal to the emf of the battery, and R is the resistance of the lamp.
The problem says that the battery is replaced with one with lower emf. Looking at the formula, this means that V decreases: if we want to keep the same brightness, we need to keep I constant, therefore we need to decrease R, the resistance of the lamp.
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Answer:
The impulse on the object is 60Ns.
Explanation:
Impulse is defined as the product of the force applied on an object and the time at which it acts. It is also the change in the momentum of a body.
F = m a
F = m()
⇒ Ft = m( -
)
where: F is the dorce on the object, t is the time at which it acts, m is the mass of the object, is its initialvelocity and
is the final velocity of the object.
Therefore,
impulse = Ft = m( -
)
From the question, m = 3kg, = 0m/s and
= 20m/s.
So that,
Impulse = 3 (20 - 0)
= 3(20)
= 60Ns
The impulse on the object is 60Ns.