A block slides along a frictionless surface and onto a slab with a rough surface. The slab has mass of 4 kg and the block has mass of 2 kg. What is the friction force on the small block at t = 1 second?

the friction force on the small block at t equals 1 second is 2N

Explanation:

Given the data in the question;

from the slope in the graph provided, we will get the acceleration of the slab

At t = 1 seconds

Slope = acceleration = ( 1 - 0) / ( 2 - 0 ) = 1/2 = 0.5 m/s²

Force = ma = 4 × 0.5 = 2 N

so by Newton's third law

Force on block will be same which is 2N

Therefore the friction force on the small block at t equals 1 second is 2N

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.