Name:______

Quiz 2 - Dynamics

K /10 T/I /10

Multiple Choice (10 K)

Identify the choice that best completes the statement or answers the question.

____ 1. What is tension?

a. / a force between two colliding objects such as a puck and a hockey stick
b. / measured using a beam balance
c. / a pushing force exerted by a string or rope
d. / a pulling force exerted by a string or rope

____ 2. Which statement is true about kinetic friction?

a. / It exists between two forces in contact at rest with respect to each other.
b. / It is a force exerted on a moving object by a surface opposite to the direction of motion.
c. / It keeps a box resting on the floor from moving.
d. / It is a force exerted on a moving object by a surface in the same direction as the motion.

____ 3. A soccer ball is rolling along the ground at 5.0 m/s. After some time, it is observed to come to a stop. Which of the following is true?

a. / Motion at a constant speed needs a net force to maintain the motion.
b. / Gravity exerts a force that stops the ball.
c. / Friction between the ball and the ground exerts a force to stop the ball.
d. / Newton’s First Law says that if the external net force on an object is zero, it cannot continue moving.

____ 4. What is the value of 1 newton as a unit of force?

a. / 1kgm2/s2
b. / 1kgm/s2
c. / 1kgm/s
d. / 1kgms2

____ 5. When an object is in equilibrium,

a. / it will stay at rest if at rest or it will come to rest if moving.
b. / it will start moving if it is at rest.
c. / the net force acting on it is zero.
d. / the net force acting on it is greater than zero.

Short Answer (10T/I)

1. Sandra pedals her bicycle with a force of 12.0 N [S]. A headwind exerts a force of 2.00 N against her motion. If the total mass of Sandra and the bicycle is 65.0 kg, what is her acceleration? (5 T/I)

2. The coefficient of kinetic friction between rubber and wet concrete is about 0.550. The driver of a car with a mass of 1050 kg locks the brakes, causing the tires to skid. Determine the force of kinetic friction acting on the car. (5 T/I)

Name:______

Answer Section

MULTIPLE CHOICE

1. ANS: D PTS: 1 REF: K/U

OBJ: 2.1 Forces and Free-Body Diagrams LOC: B2.3

MSC: Knowledge

2. ANS: B PTS: 1 REF: K/U

OBJ: 2.1 Forces and Free-Body Diagrams LOC: B2.3

MSC: Understanding

3. ANS: C PTS: 1 REF: A OBJ: 2.2 Newton's Laws of Motion

LOC: B2.3 MSC: Understanding

4. ANS: B PTS: 1 REF: K/U OBJ: 2.2 Newton's Laws of Motion

LOC: B2.3 MSC: Understanding

5. ANS: C PTS: 1 REF: K/U

OBJ: 2.3 Applying Newton's Laws of Motion LOC: B2.5

MSC: Understanding

SHORT ANSWER