Chapter 2, Forces Video Solutions, Focus on Physical Science: Grade 8, California

00:19

Problem 1

What changes when unbalanced forces act on an object?
A. mass
B. motion
C. inertia
D. weight

Donald Albin

Numerade Educator

01:42

What would be the effect of decreasing the distance between the objects?
A. The force would remain the same.
B. The force would increase because the objects are closer together.
C. The force would decrease because the objects are closer together.
D. The force only changes if the masses of the objects change.

Subash Charan

Numerade Educator

02:43

Problem 3

What force slows a book sliding on a table?
A. inertia
B. gravity
C. reaction force
D. sliding friction

Khoobchandra Agrawal

Numerade Educator

01:25

Problem 4

What does the length of a force vector represent?
A. the object's velocity
B. the force's direction
C. the force's magnitude
D. the direction of acceleration

Averell Hause

Carnegie Mellon University

01:45

Problem 5

What would cause an object to have a smaller acceleration?
A. increasing the net force on the object
B. decreasing the mass of the object, keeping the net force constant
C. increasing the mass of the object, keeping the net force constant
D. decreasing the mass of the object and increasing the net force on the object

Timothy James

Numerade Educator

03:35

Problem 6

Over which segments are the forces on the cat balanced?
A. a and c
B. b and d
C. $\mathrm{c}$ and $\mathrm{e}$
D. d only

Ahmad Reda

Numerade Educator

01:24

Problem 7

A car is driving at a constant velocity. Which is not true?
A. All the forces acting on the car are balanced.
B. A net force keeps it moving.
C. The car is moving in a straight line at a constant speed.
D. The car is not accelerating.

Ma Ednelyn Lim

Numerade Educator

02:43

Problem 8

If a student pushes a book across a table with a force of $6 \mathrm{~N}$ and the force of friction is $4 \mathrm{~N}$, what is the net force on the book?
A. $0 \mathrm{~N}$
B. $2 \mathrm{~N}$
C. $10 \mathrm{~N}$
D. $24 \mathrm{~N}$

Kristela Garcia

Numerade Educator

01:00

Problem 9

Compare the motion of an object acted on by balanced forces with the motion of an object acted on by unbalanced forces.

Keshav Singh

Numerade Educator

00:38

Problem 10

Explain how the gravitational force between Earth and the Moon would change if the distance between them increased.

Mayukh Banik

Numerade Educator

01:39

Problem 11

Create a diagram showing the following forces acting on an object. What is the net force acting on the object?

Laura Bravo

Numerade Educator

01:21

Problem 12

Compare an astronaut's weight in orbit with the astronaut's weight on Earth, assuming the mass of the astronaut does not change.

Km Neeraj

Numerade Educator

00:33

Problem 13

Imagine a book moving to the right across a table. As it slides across the table, it slows down and comes to a stop. In what direction is the net force acting on the book as it slows down?

Mayukh Banik

Numerade Educator

01:12

Problem 14

Determine whether the forces acting on a car are balanced or unbalanced if the car is turning while moving at a constant speed. Explain your answer.

Jerrah Biggerstaff

Numerade Educator

03:18

Problem 15

Infer the net force acting on a rope in a tug-ofwar if the rope is moving with a constant speed in a straight line.

Mayukh Banik

Numerade Educator

00:42

Problem 16

Give an example in which gravity speeds up a moving object and example in which gravity slows down a moving object.

Keshav Singh

Numerade Educator

00:55

Problem 17

Explain how an arrow is used to represent a force vector.

Ankit Gupta

Numerade Educator

02:15

Problem 18

Write an essay describing an example of how one of Newton's laws of motion is demonstrated in your favorite sport or activity.

Mukesh Devi

Numerade Educator

02:16

Problem 19

Determine your displacement and distance traveled if you walked $20 \mathrm{~m}$, took a book from a table, turned around and walked straight back to your seat.