The age of the Laetoli footprints was determined by:

A B horizon is:

Reverse stratigraphy would result from which of the following situations?

An example of a formation process is:

Mary Leakey’s discovery of fossil footprints in volcanic ash at Laetoli was important because:

The upper part of a soil where active organic and mechanical decomposition of geological and organic material occurs is the:

The force of gravity between two masses separated by 1 m is FF. If the distance between the masses is halved, what is the new force? A) 2F2FB) 4F4FC) F/2F/2D) F/4F/4

A 2 kg object is acted upon by two forces: 10 N10 \, \text{N} to the right and 4 N4 \, \text{N} to the left. What is its acceleration? A) 3 m/s23 \, \text{m/s}^2B) 2 m/s22 \, \text{m/s}^2C) 4 m/s24 \, \text{m/s}^2D) 6 m/s26 \, \text{m/s}^2

An arrow is shot horizontally at 50 m/s. How far does it fall vertically after 3 seconds? (Take g=10 m/s2g = 10 \, \text{m/s}^2) A) 30 mB) 45 mC) 90 mD) 150 m

When does frictional force become independent of the surface area of contact? A) AlwaysB) Only in the case of kinetic frictionC) Only in the case of static frictionD) When the object moves at constant speed