The efficiency of the device is 30 %
Explanation:
The efficiency of a heat engine is given by:
where
W is the work done by the engine
is the heat in input to the engine
For the device in this problem, we have:
W = 120 J is the work done
is the heat in input
Substituting, we find the efficiency:
which corresponds to an efficiency of 30%.
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Answer:
Explanation:
a )
Moment of inertial of four masses about axis that coincides with one side :
Out of four masses . location of two masses will lie on the axis so their moment of inertia will be zero .
Moment of inertia of the two remaining masses
= m L² + m L²
= 2 mL²
b )
Axis that bisects two opposite sides
Each of the four masses will lie at a distance of L / 2 from this axis so moment of inertia of the four masses
= 4 x m x ( L/2 )²
= 4 x mL² / 4
= m L² .
Answer:
Resistance of the second wire is twice the first wire.
Explanation:
Let us first see the formula of resistance;
R = pxL/A
Here L is the lenght of the wire, A the area and p is the resistivity of wire.
As we are given that the length of second wire is double than that of the first wire, hence the resistance of second wire would be double.
Since we have two loop in second case, inducing double voltage but as resistance is doubled so the current would remain same according to ohms law
I = V/R
Answer:
the speed of the car at the top of the vertical loop 
the magnitude of the normal force acting on the car at the top of the vertical loop 
Explanation:
Using the law of conservation of energy ;
The magnitude of the normal force acting on the car at the top of the vertical loop can be calculated as:
![F_{N} = \frac{mv^2_{top}}{R} \ - mg\\\\F_{N} = \frac{m(2.0 \sqrt{gR})^2}{R} \ - mg\\\\F_{N} = [(2.0^2-1]mg\\\\F_{N} = [(2.0)^2 -1) (50*10^{-3} \ kg)(9.8 \ m/s^2]\\\\](https://tex.z-dn.net/?f=F_%7BN%7D%20%3D%20%5Cfrac%7Bmv%5E2_%7Btop%7D%7D%7BR%7D%20%5C%20-%20mg%5C%5C%5C%5CF_%7BN%7D%20%3D%20%5Cfrac%7Bm%282.0%20%5Csqrt%7BgR%7D%29%5E2%7D%7BR%7D%20%5C%20-%20mg%5C%5C%5C%5CF_%7BN%7D%20%3D%20%5B%282.0%5E2-1%5Dmg%5C%5C%5C%5CF_%7BN%7D%20%3D%20%5B%282.0%29%5E2%20-1%29%20%2850%2A10%5E%7B-3%7D%20%5C%20kg%29%289.8%20%5C%20m%2Fs%5E2%5D%5C%5C%5C%5C)
Answer:
B.6.86 m
Explanation:
Given that
Compression in spring ,x= 9 cm
Spring constant ,K= 830 N/m
Mass of the rocket ,m= 50 g = 0.05 kg ( 1 kg = 1000 g)
Now by applying energy conservation
Now by putting the values ( we are taking g= 9.81 m/s²)
h= 6.853 m
Therefore the answer is B.
B.6.86 m
