Hola!
Percentage Error is a measurement of the discrepancy between an observed and a true, or accepted value.
[ refer the attachment. ]
According to Question,
% error =

× 100
= 2.631 % = 2.7 % (approximately.)
hope it helps!
Answer: A
Out of the screen
Explanation:
Using right hand rule, the magnetic force is perpendicular to the plane form by the magnetic field of a charged particle and its speed. Which will be into the screen.
But the negative charged particle moves in the opposite direction of the positive charged particle. Therefore, the magnetic force direction will be out of the screen
The vector, the x-component and the y-component form a rectangle triangle where the vector is the hypothenuse and the x and y components are the two sides.
Calling

the angle between the vector and the horizontal direction (x), the two sides are related to

by

where vy and vx are the two components on the y- and x-axis. Using vx=10 and vy=3 we find

And so the angle is
Answer:
F = 2(50 N) - (50 N) = 50 N
Explanation:
The direction of F is the direction in which the two students are pushing.