Answer:
m = 170 g
Explanation:
Meter stick is suspended at 40 cm mark
So here the torque due to additional mass and torque due to weight of the spring must be counter balanced
given that
1) 220 g is suspended at x = 5 cm
2) 120 g is suspended at x = 90 cm
3) mass of the scale is acting at its mid point i.e. x = 50 cm
now with respect to the suspension point the torque must be balanced
so we have
by solving above equation we have
m = 170 g
The magnitude of the frictional force is B) 300 N
Explanation:
For this problem, we just have to consider the forces acting on the box in the horizontal direction.
There are only two forces in this direction:
- The pull applied by the man, of magnitude F=300 N, forward
- The frictional force, , acting backward
So the equation of motion for the box is
where
m is the mass of the box
a is its acceleration
However, the box is at rest, so its acceleration is zero:
a = 0
This means therefore that
And so the magnitude of the frictional force is equal to the pulling force:
Learn more about friction:
#LearnwithBrainly
When a wire is moved inside uniform magnetic field then its free electrons will experience magnetic force on it due to which wire will have potential difference at its ends.
Now here we will have magnetic field due to earth and wire is moving in this constant field so induced emf is given by formula
given that
now by using the above formula we will have