Physics Ch 05 Newton's Laws

A space probe that has run out of fuel in remote outer space (where there is no friction and no other planets or stars) continues moving

• because some kind of force acts on it.

• in a curved path.

• even though no force acts on it, due to inertia

• due to gravity even though there are no planets around.

Tags

NGSS.HS-PS2-2

Consider a student standing on a bus that is waiting at a stop light. When the bus suddenly moves forward, the student falls backward. What causes the student to fall backward?

• a travel force pushes him backward

• inertia is keeping him in one spot while the bus moves forward

• gravity pulls him backward

A girl pushes a cart to the left with a 100-N force. A boy pushes it to the right with a 60-N force. The net force exerted by the two people working together is

• 100 N to the left.

• 100 N to the right.

• 40 N to the left.

• 60 N to the right.

Tags

NGSS.MS-PS2-2

When a 10-kg block is simultaneously pushed towards the east with a force of 20 N and towards the west with 15 N, the net force on the block is

• 35 N west.

• 35 N east.

• 5 N east.

• 5 N west.

Tags

NGSS.MS-PS2-2

When an object that weighs 10 N is suspended at rest by two vertical strands of rope, the tension force in EACH rope is

• slightly less than 5 N.

• 5 N

• slightly more than 5 N.

• 10 N

Answer explanation

Downward forces total 10 N (gravity), so the upward forces also must total 10N. Since it is hanging at rest, the net force must be zero.

Tags

NGSS.HS-PS2-1

Place a book that weighs 10 N on a flat, level table and the support (normal) force on the book will be

• slightly less than 10 N.

• 10 N

• slightly greater than 10 N.

• dependent on whether the book is flat or stands upright.

Tags

NGSS.MS-PS2-4

The equilibrium rule, ΣF = 0, applies to

• objects at rest.

• objects at constant velocity in a straight line.

• Both objects at rest and objects moving at a constant velocity

• None of these.

The net force on any object in equilibrium is

• zero

• 10 meters per second squared.

• equal to its weight.

• somewhat less than its weight.

Tags

NGSS.HS-PS2-1

Earth moves about 30 km/s relative to the Sun. When you jump upward in front of a wall, the wall doesn't slam into you at 30 km/s. This is because the wall

• has too little gravity to influence you.

• moves in an opposite direction to you.

• and you are moving at the same horizontal speed before, during, and after your jump.

• has negligible inertia compared with the Sun.

Tags

NGSS.MS-PS2-2

If you are not wearing a seat belt and the car you are driving hits a fixed barrier, you will hit the steering wheel with some force. This motion forward happens because

• The force of the collision has thrown you forward.

• It's an illusion and the entire car is actually speeding backwards away from the wall

• Your inertia makes you continue moving even after the car has stopped.

Tags

NGSS.MS-PS2-2