Question
what is the answer for the first question ? the true or false
1.[lpt] Select T-True, F-False, for each statement. If the first is T and the rest F, enter TFFFFF. ne to raise a box onto a platform depends on how fast it is raised. (Neglect friction, assume it starts on the ground at rest, and ends up resting on the platform) A) The work done to raise a box onto a platform depends on how fast it is raised. (N B) The work-energy principle is not valid if there are frictional forces acting. C) The kinetic energy can be positive or negative. D) The kinetic energy of an object depends on the direction of the motion involved E) The work done by a constant force acting on an object is independent of the orientation of the force relative to the motion of the object F) Work cannot be done in the absence of motion. Answer: Not yet correct, tries 3/5 Hint: If you need it, the "work-energy principle" is defined in Giancoli section 6-3 2.11pt] The graph below shows the net force applied to a 2.0 kg body, initially at rest but free to move along a straight line on a horizontal frictionless surface. The force acts along the same straight line.
Explanation / Answer
False work done depends on the force and the distance moved
work done = force x distance
B. true -work enrgy principle will be valid only if there is no friction
C . false KE = .5 x m x v^2 henc it will always be positive
D.False it does involve direction Energy is a scalar quantity
E . False Work done = FScos theta where theta is the angle between the force and the direction of motion
F.Work done = Force x distance ,if distance = 0 thus work = 0
