Hector went to the music store by heading due south at 3 m/s, then turning West and continuing at the same speed for another 3 blocks. Which of the following is true about Hector's velocity

Question

• Hector's velocity changed because his direction changed.
• Hector's velocity did not change because his speed did not change
Hector's velocity did not change because his direction did not change.
• Hector's velocity changed because his speed changed.

Answer 1

The correct statement is:

• Hector's velocity changed because his direction changed.

Velocity is a vector quantity, which means it has both magnitude (speed) and direction. Although Hector maintained a constant speed of 3 m/s, he changed his direction when he turned from south to west. Therefore, his velocity changed.

Answer 2

A car that is traveling west at a constant rate has (1 point)
• speed, but neither velocity nor acceleration.
• velocity, but neither acceleration nor speed.
• speed and velocity, but no acceleration.
• acceleration and speed, but no velocity.

Answer 3

The correct answer is:

• speed and velocity, but no acceleration.

The car is traveling west at a constant rate, which means it has a constant speed (magnitude) and a specific velocity (which includes both speed and direction). Since the rate of travel is constant, there is no acceleration acting on the car.

Answer 4

A student is investigating mass and acceleration. The student applies the same force to two boxes, as shown in the table.
Box
Force Applied to Box (newtons)
Acceleration (meters/second?)
1
20
5
2
20
2
The student claims that box 1 must have a smaller mass than box 2.
Which argument best supports the student's claim? (1 point)
Heavier objects need less force than lighter objects to accelerate at the same rate.
• Lighter objects need greater force than heavier objects to start
moving but will accelerate at the same rate.
Heavier objects need greater force than lighter objects to accelerate at the same rate.
Lighter objects need less force than heavier objects to start moving but will accelerate at the same rate.

Answer 5

The argument that best supports the student's claim is:

• Heavier objects need greater force than lighter objects to accelerate at the same rate.

Since both boxes are subjected to the same force (20 newtons) but have different accelerations (Box 1 accelerates at 5 m/s² and Box 2 at 2 m/s²), this indicates that Box 2 must have a greater mass, making Box 1 lighter in comparison. Therefore, the statement correctly explains the relationship between mass, force, and acceleration.

Answer 6

14 N
8 N
Box
Which change in force would stop this box from moving?
(1 point)
• subtracting 8 N of force pulling to the left
• subtracting 8 N of force pulling to the right
• adding 6 N of force pulling to the right
• adding 6 N of force pulling to the left

Answer 7

To determine which change in force would stop the box from moving, we need to analyze the existing forces acting on it.

If we assume that the box is currently experiencing a net force of 14 N to the left and 8 N to the right, the net force on the box would be:

\[ \text{Net Force} = 14, \text{N (left)} - 8, \text{N (right)} = 6, \text{N (to the left)} \]

To stop the box from moving, we would need to apply enough force in the opposite direction (to the right) to counteract the net force of 6 N to the left.

The correct choice is:

• adding 6 N of force pulling to the right

Adding 6 N to the right would cancel out the net force and bring the box to a stop.

Answer 8

Two forces act on an object. One force has a magnitude of 10 N directed north, and the other force has a magnitude of 2 N directed south. What is the net force on the object? (1 point)
• 8 N north
• 8 N south
• 25 N north
• 12 N south

Answer 9

To determine the net force acting on the object, we need to consider the magnitudes and directions of the forces.

1. One force is 10 N directed north.
2. The other force is 2 N directed south.

To find the net force, we subtract the southward force from the northward force:

\[ \text{Net Force} = 10, \text{N (north)} - 2, \text{N (south)} = 8, \text{N (north)} \]

Therefore, the net force on the object is:

• 8 N north