Final Wrap Up

A marble launcher shoots a marble horizontally from the height of 0.2 m above a horizontal floor. The marble lands on the floor 5 m away from the launcher. How long did the marble stay in the air?

• 0.1 s

• 0.2 s

• 0.3 s

• 0.4 s

A marble launcher shoots a marble horizontally from the height of 0.2 m above a horizontal floor. The marble lands on the floor 5 m away from the launcher. What is the initial speed of the marble?

• 5 m/s

• 10 m/s

• 15 m/s

• 25 m/s

A bicyclist moves a long a straight line with an initial velocity v0 and slows down. Which of the following the best describes the signs set for the initial position (x0), initial velocity(v0) and the acceleration (a)?

• x0 = positive v0 = positive a = negative

• x0 = Negative v0 = Positive a = Negative

• x0 = Negative v0 = Negative a = Positive

• x0 = Negative v0 = Negative a = Negative

A projectile is fired at 60 ̊ above the horizontal line with an initial velocity v0. At which of the following angles the projectile will land at the same distance as it is landed in the first trial?

• 20°

• 30º

• 40º

• 45º

When a projectile reaches the highest point the vertical component of the acceleration is:

• Greater than g

• Positive g

• Negative g

• Zero

When a projectile reaches the highest point the horizontal component of the acceleration is:

• Less than g

• Positive g

• Negative g

• Zero

The graph to the right describes the relationship between velocity and time for a moving object. What is the total displacement for the entire trip?

• 18 m

• 12 m

• 6 m

• 30 m

Position as a function of time of two moving objects is presented by the graph. Which of the following statements is true? (choose 2)

• Object I has a greater velocity than object II

• Object II has a greater velocity that object I

• At time t₀ they have the same velocity

• At time t₀ object II passes by object I

A box that weighs 25 N is pulled by an applied force of 10 N. The coefficient of static friction between the box and the surface is 0.5. The box will:

• start moving and will continue to increase its velocity

• start moving and maintain a constant velocity

• start moving and continue to increase its acceleration

• not move

• start moving and then slow to a stop

An object is thrown straight up. How do we compare the net force on the object to its weight when it is at the highest point in the path? Ignore air resistance.

• It is greater than the weight

• It is slightly less than the weight

• It is zero

• It is equal to the weight

• It can’t be determined