Answer:
750 kg.m/s
Explanation:
Momentum is the product of mass and velocity in kg.m/s.
In this case, initial momentum⇒p=m × v where m is mass and v is velocity
initial mass of car m₁=100 kg
Initial velocity of car v₁=5 m/s
Initial momentum= 100×5= 500 kg.m/s
New mass after picking two extra people m₂= 150 kg
Velocity stays the same v₂=v₁= 5 m/s
New momentum= m₂× v₂
p=150×5=750 kg.m/s
This device is a transformer.
A transformer is made of two coils. An alternating current in the first coil produces a varying magnetic field and so a varying magnetic flux through the second coil. The varying magnetic flux creates an electromotive force in the second coil, for the Faraday's law of induction, that is proportional to the variation of the flux, and this electromotive force corresponds to the new voltage on the second coil.
The relationship between the voltage in the first coil (Vp) and the voltage in the second coil (Vs) is given by
where Np and Ns are the number of turns in the primary and secondary coil, respectively.
Answer: Option (c) is the correct answer.
Explanation:
It is known that the relation between resistance, length and cross-sectional area is as follows.
R =
Let the resistance of resistor A is denoted by R and the resistance of resistor B is denoted by R'.
Hence, for resistor A the expression for resistance according to the given data is as follows.
R =
On cancelling the common terms we get the expression as follows.
R =
Now, the resistance for resistor B is as follows.
R' =
Thus, we can conclude that the statement, Wire A has the same resistance as wire B, accurately compares the resistances of wire resistors A and B.
Answer:
Efficiency of a machine is how well the machine works and what the machine is capable of doing.
Mechanical advantage=Load/Effort.
720/180=4