Dynamics_G11

Multiple Choice

In the picture, the blocks are flying out of the truck based on which of Newton's laws?

• Newton's 1st Law

• Newton's 2nd Law

• Newton's 3rd Law

• Newton's 6th Law

Multiple Choice

According to Newton's second law, if you increase the force applied to an object :

• it accelerates more

• it doesn't move

• you get more inertia

• it decelerates

Multiple Choice

When a cannon fires a cannonball we observe Newton's third law. Which force is the reaction force?

• The cannon moving forward

• The cannonball moving forward

• The cannon moving backward

• The cannonball moving backward

Multiple Choice

What is the net force?

• 5000 N right

• 4000 N right

• 40 N left

• 4000 N left

Multiple Choice

Calculate the net force acting upon the object.

• 4 N northwest

• 11.7 N northwest

• 46.0 N west

• 8 N southeast

Multiple Choice

A 20 kg bike accelerates at 10 m/s².  What was the force?

• 25 Newtons

• 20 Newtons

• 200 Newtons

• 10 Newtons

Multiple Choice

Your car has a mass of 2500 kg and a force of 5000 N. How fast will it accelerate?

• 20 m/s²

• 2 m/s²

• 0.5 m/s²

• 120 N

Multiple Choice

An evil ewok threw a rock with a force of 24.6N and an acceleration of 6m/s² at an innocent stormtrooper. What was the rocks mass?

• 4Kg

• 41kg

• 4.1kg

• 46kg

FRICTION FORCE​

​Examples of free body diagram with tension force

Multiple Choice

Name the missing force....

• weight force
• normal force
• frictional force
• tension force

Multiple Choice

The coffee cup in the picture is at rest on the table. What is true about the Normal force?

• The normal force is exactly 15

• The normal force is less than 15

• The normal force is more than 15

• The normal force is -10

Multiple Choice

The forces on this chandelier are...

• Gravity

• Gravity and Normal

• Gravity and Tension

• Gravity, Tension, Friction, and Applied

Multiple Choice

A man pushes a box across the floor at a constant velocity. Which formula describes the vertical forces on the box?

• $$F_P\ -\ F_g\ =\ 0$$

• $$F_p+F_g\ -\ F_f\ =\ 0$$

• $$F_n\ -10F_g\ =\ 0$$

• $$F_n-mg\ =\ 0$$

Multiple Choice

A box is moving to the left up a ramp. Which way is the force of friction pointing?

• down the ramp to the right
• up the ramp to the left
• there is no friction
• straight up

Multiple Select

Which force(s) are acting on big M (there may be more than one)?

• Force of Gravity

• Normal Force

• Tension

• Frictional Force

Multiple Select

Which force(s) are acting on little m (there may be more than one)?

• Tension

• Force of Gravity

• Normal Force

• Friction Force

Multiple Choice

A cup is sliding down an inclined surface that is not smooth.

What is the correct free body diagram for the cup?

Multiple Choice

A block of cheese is pulled on by a string and slides to the right along a rough surface. What is the correct free body diagram for the block of cheese?

​LEARNING OBJECTIVES :

1. ​Show a qualitative understanding of frictional forces and viscous/drag forces including air resistance.

2. Describe and explain qualitatively the motion of objects in a uniform gravitational field with air resistance.

3. Understand that objects moving against a resistive force may reach a terminal (constant) velocity.

​

Multiple Choice

When an airplane is taking off, the major forces being used are __________.

• Drag & lift

• Lift & thrust

• Weight & drag

• Thrust & weight

Multiple Choice

What is drag?

• The force that acts parallel to the interface of two surfaces that are in contact, and opposes their relative motion

• The force or forces acting to oppose the motion of an object through a fluid medium

• The inverse relationship between airflow velocity and air pressure

• The force or forces acting to promote the motion of an object through a fluid medium

Multiple Choice

Using a parachute causes a package to come to the ground slower. What statement explains this science fact?

• The package has less gravity because the parachute makes it smaller.

• The package has more gravity because the parachute catches wind and makes it heavier.

• The parachute causes air resistance and decreases the force of gravity on the object.

• The parachute causes air resistance and increases the force of gravity on the object.

Multiple Choice

The terminal velocity of an object was achieved when

• drag force balances the gravity.

• drag force is larger than gravity.

• drag force is less than the gravity.

• when drag force is zero.

Multiple Choice

Which shape is a good aerodynamic

• 1

• 2

• 3

Multiple Choice

Which object has the greatest momentum?

• 9-kg mass moving at 3 m/s

• 4-kg mass moving at 4 m/s

• 12-kg mass moving at 1 m/s

• 5-kg mass moving at 1 m/s

Multiple Choice

An object traveling at 4.0 m/s has a momentum of 16 kg.m/s. What is the mass of the object ?

• 20 kg B

• 64 kg

• 4.0 kg

• 12 kg

Multiple Choice

A 5.0 newton force impacts an impulse of 15 Newton-seconds to an object. The force acted on the object for a period of

• 75 s

• 10. s

• 20 s

• 3 s

Multiple Choice

Softer landings tend to

• increase impact force

• increase force

• increase collision time

• increase change in momentum

Multiple Choice

Cart A is pulled with a 2 Newton force for 2 seconds, and Cart B is pulled with a 1 Newton force for 3 seconds.  Which cart experiences the greatest impulse?

• Cart B

• Cart A

• they are the same

Multiple Choice

The impulse-momentum theorem states that

• the impulse on an object is equal to the change in momentum it causes 

• the force on a moving object is equal to the magnitude of the impulse.

• the impulse on an object is greater than the change in momentum it causes 

• the impulse on an object is less than the change in momentum it causes

Multiple Choice

A constant force of 4.5 N acts on a 7.2 kg object for 10.0 s. What is the change in the object's velocity? 

• 6.3 m/s

• 3.2 m/s

• 1.2 m/s 

• 4.33 m/s

Multiple Choice

If an air bag changes a 60 kg person's speed from 40.0 m/s to 0.0 m/s, what impulse must act on the person? 

•  2400 kg.m/s

• 1.5 kg.m/s

• 0.67 kg.m/s

• 1500 kg.m/s

Multiple Choice

The velocity of a 975 kg car is changed from 12.0 m/s to 27.0 m/s in 15 s by an external, constant force. What is the magnitude of the force? 

• 9.75×10² N

• 1.46×10⁴ N

• 9.75×10³ N

• 975 kg·m/s

​LEARNING OBJECTIVES :

1. State the principle of conservation of momentum.

2. Apply the principle of conservation of momentum to solve simple problems, including elastic and inelastic interactions between objects in both one and two dimensions.

3. Recall that, for a perfectly elastic collision, the relative speed of approach is equal to the relative speed of separation.

4. Understand that, while momentum of a system is always conserved in interactions between objects, some change in kinetic energy may take place.

​Example of Elastic Collision

​Example of Inelastic Collision

​2D Collision