It's very tough to use the drop-down menus for this. I'll just do the best I can without them.
-- Objects with the same charge repel each other with electrostatic force, and attract each other with gravity. You can ignore the gravity because the electrostatic force is so much stronger.
-- Objects with opposite charge attract each other with electrostatic force, and also attract each other with gravity. You can ignore the gravity because the electrostatic force is so much stronger.
-- Objects with no charge have no electrostatic force between them, and they only attract each other with gravity.
d(t) = 1.1t² + t + 1
The constant speed required to cover the same distance between t = 3 to t = 5 is the same as the average speed over that same time interval. It is given by:
v = Δx/Δt
v = average speed, Δx = change in distance, Δt = elapsed time
Given values:
Δx = d(5) - d(3) = 19.6ft
Δt = 5s - 3s = 2s
Plug in and solve for v:
v = 19.6/2
v = 9.8ft/s
The efficiency of the engine at the given useful energy and input energy is 28%.
The given parameters:
- <em>Input energy of the engine, = 125 J</em>
- <em>Useful energy of the engine, 35 J</em>
The efficiency of the engine is defined as the ratio of the output energy (useful energy) to the input energy and it is calculated as follows;

Thus, the efficiency of the engine at the given useful energy and input energy is 28%.
Learn more about efficiency of engine here: brainly.com/question/6751595
Answer:
C
Explanation:
Action and Reaction forces are equal in the opposite direction.
Answer:
Explained
Explanation:
one side of the single magnet attracted the metal surface, but repelled the stack of magnets because magnet's both poles try to attract by inducing opposite pole on the metal surface,but the pole closer to the metal is able to induce more magnetic character .so, attractive force due to this is more strong as the distance is also less as compared to the other pole.