Answer:
0.4
Explanation:
A concave lens is a diverging lens, so it will always have a negative focal length. Image distance is always negative for a concave lens because it forms virtual images.
From the lens formula;
1/f = 1/u+ 1/v
- 1/2 = 1/3 - 1/v
1/v = 1/3 + 1/2
v= 6/5
v= 1.2 cm
Magnification = image distance/object distance
Magnification = 1.2cm/3cm
Magnification = 0.4
The correct answer is: directional force
Explanation:
A vector quantity is a quantity which has both a magnitude and a direction.
A field is always associated with a force, which means that the field produces a force on an object located in the field. The force itself is a vector, since it has a magnitude and a direction.
Therefore, the magnetic field is a vector quantity since it is associated with a directional force.
Explanation:
All matter contains charged particles that are always moving therefore, all objects emit EM waves.
The relation between the magnetic field and electric field is
B_{max}= c E_{max}
The wavelength becomes shorter as the temperature of the material increases.
As frequency increases, wavelength becomes smaller.
Frequency is inversely proportional to the period of time so, when increasing the period of wave, frequency decreases, wavelength becomes larger.
wave number is inversely proportional to wave length.
so, increasing wavelength decrease the wave number.
1. wavelength increases.
2. B_max remains the same
3. polarization is same
4. wave number decreases
5. frequency decreases
6. E_max is also same
7. angular frequency decreases.
Answer:
4.24m/s
Explanation:
Potential energy at the top= kinetic energy at the button
But kinetic energy= sum of linear and rotational kinetic energy of the hoop
PE= mgh
KE= 1/2 mv^2
RE= 1/2 I ω^2
Where
m= mass of the hoop
v= linear velocity
g= acceleration due to gravity
h= height
I= moment of inertia
ω= angular velocity of the hoop.
But
I = m r^2 for hoop and ω = v/r
giving
m g h = 1/2 m v^2 + 1/2 (m r^2) (v^2/r^2) = 1/2 m v^2 + 1/2 m v^2 = m v^2
and m's cancel
g h = v^2
Hence
v= √gh
v= √10×1.8
v= 4.24m/s