A man has a power of 90 W and mass 60 kg runs up a staircase in 40 s. If each staircase is 20cm high find the number of steps? (
physics grade 9- GRAVITATION)
1 answer:
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Answer:
Net force on the wagon is 200 N
Explanation:
As we know by Newton's II law that net force on the system of mass is given as product of mass and acceleration
Here we know that
mass = 100 kg
a = 2 m/s/s
now we have
Answer:
The fraction fraction of the final energy is stored in an initially uncharged capacitor after it has been charging for 3.0 time constants is
Explanation:
From the question we are told that
The time constant
The potential across the capacitor can be mathematically represented as
Where is the voltage of the capacitor when it is fully charged
So at
Generally energy stored in a capacitor is mathematically represented as
In this equation the energy stored is directly proportional to the the square of the potential across the capacitor
Now since capacitance is constant at
The energy stored can be evaluated at as
Hence the fraction of the energy stored in an initially uncharged capacitor is
Answer:
The magnetic field is
Explanation:
From the question we are told that
The mass of the metal rod is
The current on the rod is
The distance of separation(equivalent to length of the rod ) is
The coefficient of kinetic friction is
The kinetic frictional force is
The constant speed is
Generally the magnetic force on the rod is mathematically represented as
For the rod to move with a constant velocity the magnetic force must be equal to the kinetic frictional force so
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