The answer is B because I took the test and had the question
Several information's that are required to get to the answer of the question is already given in the question. It is important to write them down first and then start solving the problem.
Force = 400 newton
Mass = 100 kg
We already know that
Force = Mass * Acceleration
Then
Acceleration = Force/Mass
= 400/100
= 4 m / S^2
The acceleration of the object is 4 m/s$2. I hope the procedure is clear for your understanding. In future you can use this method for solving such questions.
Answer:
Magnetic force, from north to south.
Explanation:
It is given that,
Mass of the ball, m = 140 g = 0.14 kg
Number of electrons,
Height, h = 110 m
Charge, q = ne
Magnetic field, B = 0.3 T
The potential energy at height of 110 meters is balanced by the kinetic energy as per the law of conservation of energy as :
Magnetic force is given by :
F = q v B
As the direction of magnetic field is from east to west, so from right hand thumb rule the direction of magnetic force is from north to south. Hence, this is the required solution.
Answer:
Torque decreases .
Explanation:
The tape is pulled at constant speed , speed v is constant , so there is
v = ω r where ω is angular speed and r is radius , As radius decreases , angular speed ω increases , So there is angular acceleration .
Let it be α . Let I be moment of inertia of reel .
Reel is in the form of disc
I = 1/2 m r²
I x α = torque
1/2 m r² x α = torque
As the reel is untapped , its mass decreases , r also decreases , so torques also decreases .
There are two possible answers:
<span>- it can move out to a higher electron shell
- </span><span> it can stay in its original shell
</span><span>
In fact, sunlight consists of photons. When sunlight hits an electron, the electron can absorbs a photon, so it gains energy: as a result, the electron can move to a higher electron shell, which corresponds to a high energy level in the atom, if the energy given by the photon is at least equal to the energy difference between the two levels. However, if the photon energy is not large enough, the electron will stay in the same shell.</span>