A toddler exerts a horizontal force of 20 N to pull a mass of 50 kg on a horizontal surface whose coefficient of static friction is 0.1. Find the static friction force and explain how you obtain your answer.

Use the table to answer question 22 23 and 24.

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

In a stagnant pool of water, a crayfish may spend much of its time lying with one side of its carapace near the surface of the water. in this position, it will move the walking legs on that side in a rhythmic back-and-forth motion. explain the likely function of this behavior.