Answer:
- Work done is maximum when the movement of object is in line and direction of force.
OR
- Work done is maximum, when displacement takes place along the direction of force.
- Work done is given by the equation
W = F.S
<em> W = F. S cos Θ</em>
<em>When cos Θ = 0° ; cos 0 = 1</em>
Answer:
All of the above
Explanation:
The magnitude of the magnetic force on a current-carrying wire held in a magnetic is given by the equation 
Where B = Strength of the magnetic field
I = The current carried by the wire
l = length of the wire in the magnetic field
θ = Angle between the wire and the magnetic field
Based on the relationship written above, the magnitude of the magnetic force on the current - carrying wire in the magnetic field depends on the strength of the magnetic field (B), length of the wire(l), current in the wire (I).
All the options are correct.
<span> For any body to move in a circle it requires the centripetal force (mv^2)/r.
In this case a ball is moving in a vertical circle swung by a mass less cord.
At the top of its arc if we draw its free body diagram and equate the forces in radial
direction to the centripetal force we get it as T +mg =(mv^2)/r
T is tension in cord
m is mass of ball
r is length of cord (radius of the vertical circle)
To get the minimum value of velocity the LHS should be minimum. This is possible when T = 0. So
minimum speed of ball v at top =sqrtr(rg)=sqrt(1.1*9.81) = 3.285 m/s
In the second case the speed of ball at top = (2*3.285) =6.57 m/s
Let us take the lowest point of the vertical circle as reference for potential energy and apllying the conservation of energy equation between top & bottom
we get velocity at bottom as 9.3m/s.
Now by drawing the free body diagram of the ball at the bottom and equating the net radial force to the centripetal force
T-mg=(mv^2)/r
We get tension in cord T=13.27 N</span>
If you multiply m (the unit for wavelength) with 1s (the unit for frequency), you will get m/s, the unit for speed. Now multiply! 25 m/s is your final answer!
