Question

raj and maria have set up this experiment. they are testing
friction force. the students wrote this hypothesis:
the rougher the surface, the more force needed to pull a block up
the ramp.
two blocks, the same size and weight, are placed on the two
ramps. one side is wood and the other side is carpeted. the
students drew this picture in their notebooks, adding an arrow to
show the pulling force that will be applied.

raj and marias teacher asked them to add to their diagram.
ms. ahern suggested that they add the friction force arrow to
their diagram, as they already had the applied or pulling force
arrow. which diagram correctly shows the friction force arrow as
the students were pulling the block up the carpeted ramp?

raj and maria should use a
force in each trial and record the measurement in

Explanation:

Step1: Understand the concept of friction force

Friction force opposes the motion. When pulling a block up a ramp, a larger arrow for friction force on the rougher (carpeted) side indicates more resistance.

Step2: Analyze the options

• Option A: Balance measures mass (grams), not force.
• Option B: Pulley is a device for redirecting force, Joules is unit of energy.
• Option C: Spring scale in grams is for mass, not force.
• Option D: Spring scale in Newtons is the correct instrument to measure force as per the SI unit for force.

Answer:

D. spring scale; Newtons