Answer:
28.8 %
Explanation:
The efficiency of an engine is given by:
where
W is the useful work done
is the heat in input
For this machine, we have
W = 15.0 kJ is the work done
is the heat exchausted to the cold reservoir, so the total amount of heat in input is
And so the efficiency is
which corresponds to 28.8 %.
Answer:
1.1 sec
Explanation:
m = mass of the box = 8 kg
k = spring constant of the spring = 69 N/m
v = initial speed of the box = 1.5 m/s
t = time period of oscillation of box in contact with the spring
Time period is given as
Inserting the values
t = 1.1 sec
Answer:
Explanation:
We are given that
Initial velocity=u=18ft/s
Final velocity,v=38ft/s
Time=t=3 s
We have to find the average acceleration over that 3 s period.
We know that
Average acceleration,a=
Using the formula
Average acceleration,a=
Average acceleration,a=
Average acceleration,a=
Hence, the average acceleration=
Answer:
the only effect it has is to create more induced charge at the closest points, but the net face remains zero, so it has no effect on the flow.
Explanation:
We can answer this exercise using Gauss's law
Ф = ∫ e . dA = / ε₀
field flow is directly proportionate to the charge found inside it, therefore if we place a Gaussian surface outside the plastic spherical shell. the flow must be zero since the charge of the sphere is equal induced in the shell, for which the net charge is zero. we see with this analysis that this shell meets the requirement to block the elective field
From the same Gaussian law it follows that if the sphere is not in the center, the only effect it has is to create more induced charge at the closest points, but the net face remains zero, so it has no effect on the flow , so no matter where the sphere is, the total induced charge is always equal to the charge on the sphere.
Answer:
Yes we can find the initial velocity of car without finding acceleration.
u = 10 m/s.
Explanation:
Given that
s=20 m
Car takes 4 s to come in rest.
We know that when acceleration is constant then we can apply motion equation
----------1
------2
From equation 1 and 2
So we can say that
Given that the velocity of car at final condition will be zero (v=0)
From the above equation we can find the initial velocity of car without finding the acceleration
u = 10 m/s