1. how does an inclined plane help make it easier to do work on a heavy object?
A. it reduces the amount of friction on the object
B. it reduces the total amount of work needed by increasing the force
C. It reduces the amount of force needed by increasing the distance
D. It reduces the amount of force needed by increasing the distance
2. a student is sledding down a hill traveling 6 m/s. The sled can fit up to three students. which change would increase the kinetic energy of the sled the most?
A. decrease the speed of the sled to 3 m/s
B. Increase the speed of the sled to 12 m/s
C. Add two more students to the sled traveling 6 m/s
D. Add one more student to the sled and decrease the speed to 3 m/s
Note for #1 that both C and D say the same thing. That's the correct answer.
2. KE = 1/2 *m*v^2
You get more bang for the buck by choosing 12 m/s.
I’m screwed for the test:(
1. C and D are the same ... and correct
2. K.E. is directly related to the mass and the square of the velocity
... adding two more students triples the K.E.
... doubling the velocity quadruples the K.E. ... because of the square factor
1. The correct answer is C. It reduces the amount of force needed by increasing the distance.
An inclined plane is a simple machine that is a flat surface raised at an angle. It allows for easier work on a heavy object by reducing the amount of force needed to move the object vertically. By increasing the distance over which the object is moved, the inclined plane allows the force to be spread out, reducing the amount of force required.
To understand why, let's consider a scenario where you are lifting a heavy object directly upwards without an inclined plane. In this case, you have to apply a large force over a relatively short distance to lift the object. However, if you use an inclined plane, you can push or pull the object along the inclined surface, which increases the distance covered. As a result, you can apply a smaller force over a longer distance, making it easier to move the object.
2. The correct answer is B. Increase the speed of the sled to 12 m/s.
Kinetic energy is the energy an object possesses due to its motion. The formula for kinetic energy is given by KE = 1/2 * mass * velocity^2, where mass is the mass of the object and velocity is its speed.
To increase the kinetic energy of the sled the most, we need to focus on increasing the velocity since it is squared in the equation. Among the given options, increasing the speed of the sled to 12 m/s would result in the greatest increase in kinetic energy. This is because the squared term amplifies any change in velocity.
Option A decreases the speed, which would decrease the kinetic energy. Option C adds more students, resulting in an increase in mass, but since the squared term multiplies the velocity, it has a smaller impact compared to increasing the velocity. Option D decreases the speed and does not have as significant an effect as increasing the velocity.
Therefore, option B, increasing the speed of the sled to 12 m/s, would increase the kinetic energy of the sled the most.