Answer:
C
Sign-Negative
Explanation:
We are given that
Electric field =
(Radially downward)
Acceleration=
(Upward)
Mass of charge=3 g=
kg
1kg=1000g
We have to find the magnitude and sign of charge would have to be placed on a penny .
By newton's second law


Substitute the values then we get

Substitute the values then we get




C
Sign of charge =Negative
Because electric force acting in opposite direction of electric field therefore,charge on penny will be negative.
Neutron is commonly used to initiate a fission chain reaction.
As the satellite panels extend, the angular velocity decreases due to drag force, and hence it will cause a decrease in the angular momentum of the satellite.
<h3>
What is angular momentum?</h3>
Angular momentum is defined as the quantity of rotation of a body, which is the product of mass, velocity and radius.
L = mvr
L = mωr²
where;
- m is mass of the object
- v is velocity
- r is radius
- ω is angular velocity
As the satellite panels extend, the angular velocity decreases due to drag force, and hence it will cause a decrease in the angular momentum of the satellite.
Learn more about angular momentum here: brainly.com/question/4126751
#SPJ1
Expand each vector into their component forms:

Similarly,


Then assuming the resultant vector
is the sum of these three vectors, we have


and so
has magnitude

and direction
such that

Answer:
NO
Explanation:
No, a machine cannot be 100% efficient. This is due to the movement of the moving parts siding against each other and causing friction. This friction is the one that creates heat and causes wear and tear between moving ports f the machine hence making the machine to decrease in efficiency with time