this is a monopole, right?!?! in practise, do you get electrical monopoles, or magnetic monopoles?
field lines show the direction that (electric field) a free positive charge would travel, or (magnetic field) the direction in which s compass would show as north.
i think that is what you need to know.
Answer:
i) 21 cm
ii) At infinity behind the lens.
iii) A virtual, upright, enlarged image behind the object
Explanation:
First identify,
object distance (u) = 42 cm (distance between object and lens, 50 cm - 8 cm)
image distance (v) = 42 cm (distance between image and lens, 92 cm - 50 cm)
The lens formula,
Then applying the new Cartesian sign convention to it,
Where f is (-), u is (+) and v is (-) in all 3 cases. (If not values with signs have to considered, this method that need will not arise)
Substituting values you get,
i)
f = 21 cm
ii) u =21 cm, f = 21 cm v = ?
Substituting in same equation
v ⇒ ∞ and image will form behind the lens
iii) Now the object will be within the focal length of the lens. So like in the attachment, a virtual, upright, enlarged image behind the object.
Complete question is: You pull your car into your driveway and stop. The drive shaft of your car engine, initially rotating at 2400 rpm,slows with a constant rotational acceleration of magnitude 30 rad/s². How long does it take for the drive shaft to stop turning?
Answer:
8.37 s
Explanation:
Initial rotational velocity, ω₀ = 2400 rpm = 2400 × 2π/60 = 251.2 rad/s
Final velocity, ω = 0
rotational deceleration, α =- 30 rad/s²
Use the first equation of rotational motion:
Substitute the values:
To make the motor turn faster we can:
(a) increase the current
(b) use stronger magnets
(c) push the magnets closer to the coil
(d) put an iron centre piece into the coil
(e) adding more sets of coils
Answer:using Newton third law
Let initial velocity of block be u1=3m/s
Mass of moving block m1 =1kg
Final velocity of block =V
Mass of stationary block m2= 4kg
Since they stick together, their final velocity will be the same.
m1u1 + m2u2=(m1+m2)v
(1*3)+(0*4)=(1+4)v
3=5v
Divide both sides by 5
V=0.6
Final velocity is 0.6m/s
Explanation: