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.
Complete Question
The complete question is shown on the first uploaded image
Answer:
The value is 
Explanation:
From the question we are told that
The mass of the wheel is m = 6.9 kg
The radius is 
The radius of gyration is 
The angle is 
The force which the massless bar is subjected to 
Generally given that the wheels rolls without slipping on the flat stationary ground surface, it implies that point A is the center of rotation.
Generally the moment of inertia about A is mathematically represented as

Here
is the moment of inertia about G with respect to the radius of gyration which is mathematically represented as

=>
=>
=>
Generally the torque experienced by the wheel is mathematically represented as

=> 
=> 
Generally this torque is also mathematically represented as

=> 
=> 
Yes you are right but sometimes just because a number is bigger doesnt always make it so.
First take note that you're figuring 10am and 1pm. Their temperatures are 77 degrees and 83 degrees
To solve subtract 83-77=6
So it rose 6 degrees.