What is the thickness of the mantle in km?

Rubber on floor tile has a coefficient of kinetic friction of 1.0 and a coefficient of static friction of 2.0. how much force would a 3.5 lb. robot need to produce in order to start moving?

The electric field direction is defined by the direction of the force felt by (select one of the following answers): 1. a negative charge. 2. a positive charge. 3. both positive and negative charges.

In which situation is the acceleration of a car negative? question 5 options: a)the velocity of a car was 75 km/hr over 4 hours. b)the velocity of a car reduced from 50 km/hr over one minute. c)the velocity of a car increased from 40 km.h to 75 km/h over 15 minutes. d)the velocity of a car was 45 km/hr at 2: 00pm and at 4: 00pm its velocity was 85 km/ht.