Multiple Choice
In the figure, two identical ideal massless springs have unstretched lengths of 0.25 m and spring constants of 700 N/m. The springs are attached to a small cube and stretched to a length L of 0.30 m as in Figure A. An external force P pulls the cube a distance D = 0.020 m to the right and holds it there. (See Figure B.) The external force P, that holds the cube in place in Figure B, is closest to
A) 28 N.
B) 25 N.
C) 21 N.
D) 18 N.
E) 14 N.
Correct Answer:

Verified
Correct Answer:
Verified
Q29: How much energy is needed to change
Q30: In the figure, a 700-kg crate is
Q31: A graph of the force on an
Q33: A constant horizontal pull acts on a
Q35: Block A (0.40 kg) and block B
Q36: Find the net work done by friction
Q38: An airplane flies 120 km at a
Q39: The work performed as a function of
Q40: The coefficient of the restitution of an
Q54: A worker lifts a 20.0-kg bucket of