Answer:

Explanation:
As we know that the radius of the circular motion is given as

time period of the motion is given as

now we know that it is moving with uniform speed
so it is given as

now plug in all data


The brightness of the lamp is proportional to the current flowing through the lamp: the larger the current, the brighter the lamp.
The current flowing through the lamp is given by Ohm's law:

where
V is the potential difference across the lamp, which is equal to the emf of the battery, and R is the resistance of the lamp.
The problem says that the battery is replaced with one with lower emf. Looking at the formula, this means that V decreases: if we want to keep the same brightness, we need to keep I constant, therefore we need to decrease R, the resistance of the lamp.
Answer:
Given the area A of a flat surface and the magnetic flux through the surface
it is possible to calculate the magnitude
.
Explanation:
The magnetic flux gives an idea of how many magnetic field lines are passing through a surface. The SI unit of the magnetic flux
is the weber (Wb), of the magnetic field B is the tesla (T) and of the area A is (
). So 1 Wb=1 T.m².
For a flat surface S of area A in a uniform magnetic field B, with
being the angle between the vector normal to the surface S and the direction of the magnetic field B, we define the magnetic flux through the surface as:

We are told the values of
and B, then we can calculate the magnitude

It is customary to work in SI units.
Calculate the volume of the concrete.
V = 3.7*2.1*5.8 cm³ = 45.066 cm³ = 45.066 x 10 ⁻⁶ m³
The mass is 43.8 g = 43.8 x 10⁻³ kg
The density is mass/volume.
Density = (43.8 x 10⁻³ kg)/(45.066 x 10⁻⁶ m³) = 971.9 kg/m³
Answer: 971.9 kg/m³
Explanation:
Given Data:
mass of dog = 12 Kg
dog's center of mass = 0.20m
length of dog = 0.50m
height of dog's jump = ?
Solution:
Work done of gravitational force = Gain in Potential energy
2.1 × mgΔh = mg (h - 0.1)
2.1 × (0.3 - 0.1) = (h - 0.1)
h = 0.52 m