True statements about motion in a straight line. Chose two options from the list.?

Question

A. An object which is slowing down must have negative velocity.

B. If a value has zero velocity, it must be stationary.

C. The graph of position against time for a vehicle with constant acceleration has to be a straight line.

D. Acceleration is the rate of change of velocity.

E. Velocity is the rate of change speed

F. A reversing vehicle must have negative velocity.

G. If two vehicles have the same velocity-time graphs, then they must have the same position-time graphs.

Answer 1

B, C, D,

http://www.theclickinfo.com/cse:straight...

Answer 2

D

There is no other correct answer besides D unless you define the velocity in relative term! For example a reversing vehicle has a negative velocity only relative to a fixed reference which you have not stated. Also, If a value has a zero velocity, it must be stationary relative to what? How about changing direction without moving; you can't define an object stationary if it changes direction without having a traslational motion!

Answer 3

B and D

A) negative acceleration

B)

C) parabola

D) a=dV/dt

dV=change of velocity

dt= time taken

so

dV/dt=rate of change of velocity

E) displacement

F) If the initial velocity is negative the reverse will be positive

G) if they have been initially at the same spot.