Ch 4: Mechanics I

Question 1

True or False?

An unbalanced force on an object will always change the object’s direction.

Answer 1

False. It could change the speed without changing its direction.

Question 2

True or False?

An unbalanced force on a body will always impact the object’s speed.

Answer 2

False. It will always impact the VELOCITY, but it could change only the speed or only the direction.

Question 3

[Inclined planes]

the force due to gravity acting parallel to the inclined plane = ________

Answer 3

mg sin θ

Question 4

[Inclined planes]

the force due to gravity acting perpendicular to the inclined plane = ________
(use this when calculating the normal force)

Answer 4

mg cos θ

p. 88