A toy cart is initially at rest. A constant force of 10 N is ... ...

  A toy cart is initially at rest. A constant force of 10 N is applied horizontally for 20 seconds, so the cart begins to move along the level frictionless floor. What is the kinetic energy of the cart just after the 20 seconds?
(A) 100 Joules
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in 09. Energy