Answer:
Explanation:
The torque of a force is given by:
where
F is the magnitude of the force
d is the distance between the point of application of the force and the centre of rotation of the system
is the angle between the direction of the force and d
In this problem, we have:
, the force
, the distance of application of the force from the centre (0,0)
, the angle between the direction of the force and a
Therefore, the torque is
I believe (D) during the second half of the trampoline's movement downward and the first half of the trampoline's movement upward.
But this question is hard to answer. So it can also be C.
Answer:
C. 85%
Explanation:
A cylinder fitted with a piston exists in a high-pressure chamber (3 atm) with an initial volume of 1 L. If a sufficient quantity of a hydrocarbon material is combusted inside the cylinder to produce 1 kJ of energy, and if the volume of the chamber then increases to 1.5 L, what percent of the fuel's energy was lost to friction and heat?
A. 15%
B. 30%
C. 85%
D. 100%
work done by the system will be
W=PdV
p=pressure
dV=change in volume
3tam will be changed to N/m^2
3*1.01*10^5
W=3.03*10^5*(1.5-1)
convert 0.5L to m^3
5*10^-4
W=3.03*10^5*5*10^-4
W=152J
therefore
to find the percentage used
152/1000*100
15%
100%-15%
85% uf the fuel's energy was lost to friction and heat
Answer:
A)The electric field at a point cannot be in two different directions and therefore two field lines can never cross.
E)If equipotential lines of different potentials cross that would imply that the potential at that point has two different values and that is not physically possible.
Explanation:
A) Field lines cannot be crossed. Otherwise, at the point where the lines cross, there would be two different electric field vectors, which makes no physical sense.
E) Since the electric field is a conservative vector field, it can be defined as the negative value of the gradient of the electric potential, therefore, the same is true as in the previous point.
