Subject :NSO Class : Class 8
Richa conducted an experiment as shown in the figure to investigate how the height of the ramp affects the amount of force needed to move a wooden block up the ramp.
Which of the following variables must be kept the same to ensure that her experiment is fair?
I. Number of bricks
II. Material of the ramp
III. Size of the wooden block
IV. Mass of the wooden block
AI, II and III only
BI, III and IV only
CII, III and IV only
DI, II, III and IV