Explanation:
It is given that,
Mass of the object, m = 0.8 g = 0.0008 kg
Electric field, E = 534 N/C
Distance, s = 12 m
Time, t = 1.2 s
We need to find the acceleration of the object. It can be solved as :
m a = q E.......(1)
m = mass of electron
a = acceleration
q = charge on electron
"a" can be calculated using second equation of motion as :




a = 16.67 m/s²
Now put the value of a in equation (1) as :


q = 0.0000249 C
or

Hence, this is the required solution.
Answer:
Diverging lens
Explanation:
Given parameters:
Power of lens = -2.0D
Unknown:
Focal length = ?
Solution:
The power of lens is the reciprocal of the focal length;
P =
where f is the focal length
f =
=
The lens is a diverging lens
Answer:
Explanation:
Average acceleration
is the variation of velocity
over a specified period of time
:
Where:
being
the initial velocity and
the final velocity (according to the information given from the described graph)

Then:
Answer:
(d) Negative.
Explanation:
let's test each at a time.
(a) It can't be 0, because cup would slide back other wise.
(b) Positive, well if forward is positive, than the work done against the forward acceleration must be negative , so it can't be positive.
(c) Equal to non-conservative work done by the car's engine.
well no, because work done by car's engine dosen't go all of it into getting car to move, so it can't be that.
(d) negative, this look like it, because work that friction does must be nagative to counteract positive thrust of car which is positive and in forward direction.
(d) this can't be true.
So the answer is (d) negative.