Question

matching: match the measurement property to the correct unit.

1. m/s²
2. kg
3. kg*m/s
4. newtons (n)
5. m/s

a. mass
b. velocity
c. acceleration
d. momentum
e. force
matching: match the word with the correct definition.

1. any push or pull on an object
2. resistance to change in velocity
3. the sum of all forces on an object

a. force
b. net force
c. inertia
multiple choice

1. an object at rest will stay at rest, and an object in motion will stay in motion at constant velocity unless acted upon by a/an ______________ force.

a. residual
b. constant
c. balanced
d. unbalanced

1. a book on a table stays in place because the forces acting on it are ____________________.

a. unbalanced
b. upward
c. downward
d. balanced

1. the rate at which objects accelerate to the earth ______________.

a. 10.8 m/s²
b. 9.8 m/s²
c. 8.8 m/s²
d. all of the above

Explanation:

• 1 - 5:
• Acceleration (\(a\)) has the formula \(a=\frac{\Delta v}{\Delta t}\), where \(\Delta v\) is in \(m/s\) and \(\Delta t\) is in \(s\), so the unit of acceleration is \(m/s^{2}\).
• Mass (\(m\)) has the SI unit \(kg\).
• Momentum (\(p\)) is given by \(p = mv\), where \(m\) is in \(kg\) and \(v\) is in \(m/s\), so the unit of momentum is \(kg\cdot m/s\).
• Force (\(F\)) is given by \(F=ma\), with \(m\) in \(kg\) and \(a\) in \(m/s^{2}\), and \(1N = 1kg\cdot m/s^{2}\), so the unit of force is \(N\).
• Velocity (\(v\)) has the formula \(v=\frac{d}{t}\), where \(d\) is in \(m\) and \(t\) is in \(s\), so the unit of velocity is \(m/s\).
• 6 - 8:
• By definition, force is any push or pull on an object.
• Inertia is the resistance of an object to change in its velocity (a property related to mass).
• Net force is the vector sum of all forces acting on an object.
• 9:
• According to Newton's first law, an object at rest stays at rest and an object in motion stays in motion with a constant velocity unless acted upon by an unbalanced force.
• 10:
• A book on a table has two forces acting on it: gravitational force (downward) and normal force (upward). Since the book is at rest, these forces are balanced (\(F_{net}=0\)).
• 11:
• The acceleration due to gravity near the Earth's surface is approximately \(g = 9.8m/s^{2}\).

Answer:

1. C
2. A
3. D
4. E
5. B
6. A
7. C
8. B
9. D
10. D
11. B