Question 1
which of the following is an example of a force?
a. electrons moving toward a positive charge
b. a child kicking a soccer ball
c. air pushing against a falling object
d. all of the above
question 2
tension force is an example of a contact force.
a. true
b. false
question 3
a frictional force is the force exerted by a surface as an object moves across it; therefore, it is considered a contact force.
a. true
b. false
question 4
which of the following best describes normal force?
a. the force of attraction between two objects
b. the force applied to an object by a push or a pull
c. the force transmitted through a string, rope, or wire
d. the support force exerted on an object which is in contact with another stable object
question 5
if a leaf falls from a tree and we assume that it is in free fall and not affected by air resistance, how many force vectors does the leaf have?
a. 0
b. 1
c. 2
d. 3
question 6
if you kick a ball and the ball does not move, then the forces involved must
a. unbalanced
b. balanced
c. directional
d. weighted
question 7
as the distance between two objects gets larger, the gravitational force between them gets larger too.
a. true
b. false
question 8
when an astronaut is in space, his or her body is acted upon by an increased gravitational force from the earth.
a. true
b. false
question 9
the mass of an object cannot change, but the weight of an object can change.
a. true
b. false
question 10
use the following image to answer the question.
in the above diagram, the force vectors are equal in magnitude and opposite in direction.
a. true
b. false
(the picture is for number 10)