A car’s engine provides a forward force of 2000 N while the force of air resistance is 800 N in the opposite direction. With what force will the car move, and in which direction?

Question

Responses:

16000 N forward

1200 N backward

1200 N forward

2800 N forward

Answer 1

To determine the net force acting on the car, we need to subtract the force of air resistance from the forward force provided by the engine. The engine provides a forward force of 2000 N, and the force of air resistance acts in the opposite direction with a magnitude of 800 N.

Net Force = Forward Force - Air Resistance Net Force = 2000 N - 800 N Net Force = 1200 N

The car will move in the direction of the net force, which is forward.

Therefore, the correct response is: 1200 N forward.

Answer 2

Two movers are attempting to push a couch up a ramp. One mover applies a force of 80 N to the right, but the force of friction between the couch and the ramp is providing a force of 110 N in the opposite direction, and the couch slides down the ramp.

At minimum, how much force will the second mover need to apply to help push the couch up the ramp?

Responses:

31 N

30 N

80 N

110 N

Answer 3

To determine how much force the second mover needs to apply to push the couch up the ramp, we first need to calculate the total force acting on the couch.

The first mover applies a force of 80 N to the right (up the ramp) and the force of friction opposing this motion is 110 N (down the ramp).

The net force acting on the couch can be calculated as follows:

Net Force = (Force applied by mover 1) - (Force of friction) Net Force = 80 N - 110 N Net Force = -30 N

This negative value indicates that the couch is sliding down the ramp. To overcome the friction and push the couch up the ramp, the second mover must provide enough force to counteract the total frictional force.

To start moving the couch up the ramp, the total force that needs to be applied is at least equal to the force of friction minus the force already applied by the first mover:

Force required (F) = Force of friction - Force applied by mover 1 Force required = 110 N - 80 N Force required = 30 N

Therefore, at minimum, the second mover would need to apply 30 N to help push the couch up the ramp.

The correct response is: 30 N.

Answer 4

A group of students conduct an experiment to study Newton’s second law of motion. They applied a force to a toy car and measure its acceleration. The table shows the results.

Force (N) Acceleration (m/s²)
2.0 5.0
3.0 7.5
6.0 15.0
If the students graph the data points, which conclusion will they be able to make?

Responses

The data points will not fall along a line. This shows that as the force increases, the acceleration increases.

The data points will fall along a line. This shows that as the force increases, the acceleration decreases.

The data points will fall along a line. This shows that as the force increases, the acceleration increases.

The data points will not fall along a line. This shows that as the force increases, the acceleration decreases.

Answer 5

According to Newton's second law of motion, the relationship between force (F), mass (m), and acceleration (a) is given by the equation:

\[ F = m \cdot a \]

This means that for a given mass, if the force increases, the acceleration should also increase proportionally.

In the data provided:

• For a force of 2.0 N, the acceleration is 5.0 m/s².
• For a force of 3.0 N, the acceleration is 7.5 m/s².
• For a force of 6.0 N, the acceleration is 15.0 m/s².

If we analyze the ratios of force to acceleration:

1. \( \frac{2.0 , \text{N}}{5.0 , \text{m/s}^2} = 0.4 \)
2. \( \frac{3.0 , \text{N}}{7.5 , \text{m/s}^2} = 0.4 \)
3. \( \frac{6.0 , \text{N}}{15.0 , \text{m/s}^2} = 0.4 \)

Since the ratio of force to acceleration is constant (0.4), this indicates a linear relationship between the force and acceleration, meaning that as the force increases, the acceleration increases as well.

Given this analysis, the correct conclusion would be:

The data points will fall along a line. This shows that as the force increases, the acceleration increases.

Answer 6

In the experimental setup shown, a car has one end of a string attached to it, and the other end is attached to a fixed number of metal discs. The car moves along the table and two probes sense the motion of the car. The probes send information to a computer that displays the acceleration and velocity of the experiment. When looking at these results, which quantity stays constant during the trials?





Responses

velocity

mass

force

acceleration

Answer 7

In an experimental setup where a car is moving and attached to a fixed number of metal discs through a string, several conditions can affect the measurement of acceleration, velocity, and force. However, if the setup is designed in such a way that the mass of the car and metal discs remains unchanged throughout the trials, then the mass of the car would stay constant.

Here's a brief explanation of the other quantities:

• Velocity changes as the car accelerates or moves at different speeds.
• Force may vary depending on how the car is being pulled by the discs or any other external factors that may influence motion (like friction).
• Acceleration could also vary depending on the net force acting on the car and its mass according to Newton's second law (\(F = m \cdot a\)).

Therefore, the correct answer is:

mass.

Answer 8

magine a scenario in which an animal's force is pushing itself forward 5 N, friction is pushing it 4 N backward, gravity is pushing the animal 10 N down, and the animal is pushing itself 10 N up. Describe the movement of the animal.
Responses

It moves forward and upward because those are the greatest net forces.

It only moves forward because there is a net force forward.

It moves 10 N down and 10 N up as those are the greatest forces acting on the animal.

It moves 29 N forward because that's the net force.

Answer 9

To analyze the movement of the animal based on the given forces, we can calculate the net forces acting in the forward/backward direction and the upward/downward direction.

Forces acting on the animal:

1. Forward Force: 5 N
2. Backward Force (friction): 4 N
3. Upward Force: 10 N
4. Downward Force (gravity): 10 N

Calculating the net forces:

1. Net Force in the Forward/Backward Direction: \[ \text{Net Force Forward} = \text{Forward Force} - \text{Backward Force} \] \[ \text{Net Force Forward} = 5 , \text{N} - 4 , \text{N} = 1 , \text{N} , \text{(forward)} \]

2. Net Force in the Upward/Downward Direction: \[ \text{Net Force Upward} = \text{Upward Force} - \text{Downward Force} \] \[ \text{Net Force Upward} = 10 , \text{N} - 10 , \text{N} = 0 , \text{N} \] This means there is no net movement in the vertical direction as the upward and downward forces cancel each other out.

Final Movement Analysis:

• The animal experiences a net force of 1 N in the forward direction.
• There is no net force in the vertical direction (up and down forces cancel each other).

Based on this analysis, the movement of the animal can be described as:

It only moves forward because there is a net force forward.

Answer 10

Two rockets with the same mass are accelerated. Rocket A accelerates twice as quickly as rocket B. Which statement is correct?
Responses

The motor in rocket A is four times as powerful as the motor in rocket B.

The motor in rocket A is equally as powerful as the motor in rocket B.

The motor in rocket A is half as powerful as the motor in rocket B.

The motor in rocket A is twice as powerful as the motor in rocket B.

Answer 11

To analyze the relationship between acceleration, force, and power, we can use Newton's second law of motion and the definition of power.

Newton's second law states: \[ F = m \cdot a \] Where:

• \( F \) is the force applied,
• \( m \) is the mass,
• \( a \) is the acceleration.

Power is defined as the work done per unit time, and it can also be expressed as: \[ P = F \cdot v \] Where \( v \) is the velocity of the object. However, for constant mass and considering acceleration, we can relate the force to power:

1. Given Information:
   • Both rockets have the same mass \( m \).
   • Rocket A accelerates twice as quickly as Rocket B.

Let’s denote the acceleration of Rocket B as \( a \), which means the acceleration of Rocket A is \( 2a \).

2. Calculating Forces:

   • The force exerted by Rocket A can be expressed as: \[ F_A = m \cdot (2a) = 2m \cdot a \]
   • The force exerted by Rocket B is: \[ F_B = m \cdot a \]

3. Comparing Forces:

   • From the above, we can see that: \[ F_A = 2F_B \]
   • This means the force exerted by Rocket A is twice that of Rocket B.

4. Determining Power:

   • Since both rockets are effectively performing similar tasks but at different accelerations, and given that force is doubled, Rocket A's motor needs to be more powerful to produce this greater force at the same rate of doing work.

Because power is proportional to force when moving at the same speed (since we are looking directly at the engines), we conclude that:

• If Rocket A's force is twice that of Rocket B, then the power of Rocket A's motor must also be twice that of Rocket B's motor to achieve that force.

Therefore, the correct statement is:

The motor in rocket A is twice as powerful as the motor in rocket B.