Dynamics

A book is lying at rest on a table. The book will remain there at rest because:

• there is a net force but the book has too much inertia

• there are no forces acting on it at all

• it does move, but too slowly to be seen

• there is no net force on the book

A hockey puck slides on ice at constant velocity. What is the net force acting on the puck?

• more than its weight
• equal to its weight
• less than its weight but more than zero
• zero

You put your book on the bus seat next to you. When the bus stops suddenly, the book slides forward off the seat. Why?

• a net force acted on it
• no net force acted on it
• it remained at rest
• it did not move, but only seemed to

You kick a smooth flat stone out on a frozen pond. The stone slides, slows down and eventually stops. You conclude that:

• the force pushing the stone forward finally stopped pushing on it
• no net force acted on the stone
• a net force acted on it all along
• the stone simply �ran out of steam�

Consider a cart on a horizontal frictionless table. Once the cart has been given a push and released, what will happen to the cart?

• slowly come to a stop
• continue with constant acceleration
• continue with decreasing acceleration
• continue with constant velocity

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

We just decided that the cart continues with constant velocity. What would have to be done in order to have the cart continue with constant acceleration?

• push the cart harder before release
• push the cart longer before release
• push the cart continuously
• change the mass of the cart

A very large truck sits on a frozen lake. Assume there is no friction between the tires and the ice. A fly suddenly smashes against the front window. What will happen to the truck?

• it is too heavy, so it just sits there
• it moves backward at const. speed
• it moves forward at const. speed
• it accelerates forward

What can you say about the force of gravity Fg acting on a stone and a feather?

• Fg is greater on the feather
• Fg is greater on the stone
• Fg is zero on both due to vacuum
• Fg is equal on both always

Tags

NGSS.MS-PS2-4

What can you say about the acceleration of gravity acting on the stone and the feather?

• g is greater on the feather

• g is greater on the stone

• g is zero on both due to vacuum

• g is equal on both always

Tags

NGSS.MS-PS2-4

An astronaut on Earth kicks a bowling ball and hurts his foot. A year later, the same astronaut kicks a bowling ball on the Moon with the same force. His foot hurts...

• more
• less
• the same

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

NGSS.MS-PS2-4