These are multiple-choice questions:

1.How much work is accomplished when a force of 300 N pushes a box across the floor for a distance of 100 M?
A- 300 N
B- 30,000 N
C- 300 J
D- 30,000 J
I chose D

2.How do simple machines make work easier?
A- They change the strength or direction of a force
B- They apply force quickly
C- They decrease the power available
D- They maintain the distance of a force
I chose A

3.What has changed when a gardener uses a lever to lift a rock, instead of lifting it by hand?
A- More force is applied over the longer distance
B- Less force is applied over a longer distance
C- More forcec is applied over a shorter distance
D- Less force is applied over a shorter distance
I chose D...?

4.Liz is on a swing. When Liz approaches the highest point, what is true about her potential and kinetic energy?
A- Potential and kinetic energy are equal.
B- Potential and kinetic energy are at zero.
C- Potential energy is at lowest, and kinetic energy is at highest
D- Potential energy is at highest, and kinetic energy is at lowest.
I wasn't sure about this one but I chose C

5.When the temperature of an object increases, what happens to the kinetic energy of the particles in the object?
A- It decreases
B- It increases
C- It is conserved
D- It equals zero
I think it might be A or B...

Thanks so much!!
-MC

You are correct with 1 and 2. You are wrong with 3 and 4, and should try to give each problem more thought. One of your answers for 5 is right and the other is wrong. You seem to me taking wild guesses instead of thinking about what potential energy and temperatiure really means.

OK, I've been trying my best and for 3 I got B and for five I got B...? 4 still seems really tricky to me!

-MC

3B is correct

4. Potential energy increases with height above the ground. At the top of the swing, the velcoity is zero.

5. When heat is added to a mass (and the temperatuire rises), that energy must go somewhere. It goes to make the molecules move faster.

THANK YOU!!

-MC

So number 4 is actually D

-MC

Yes!

30,000N

work=force times distance
300 times 100= 30,000

If you are confused on one and you cant find the answer on a website, go into the lesson again or look in your text book if you have one.

1. To determine the work done when a force is applied to move an object, you need to multiply the force by the distance the object moves in the direction of the force. So, in this case, the force is 300 N and the distance is 100 M. To calculate the work done, you need to multiply these values: 300 N * 100 M = 30,000 N·M. Since the unit for work is joules (J), the correct answer is D - 30,000 J.

2. Simple machines make work easier by changing the strength or direction of a force. They allow us to apply a smaller force over a longer distance to accomplish the same amount of work. So, the correct answer is A - They change the strength or direction of a force.

3. When a gardener uses a lever to lift a rock instead of lifting it by hand, less force is applied over a shorter distance. The lever allows the gardener to magnify the force applied with a smaller input force over a shorter distance. So, the correct answer is D - Less force is applied over a shorter distance.

4. When Liz approaches the highest point on a swing, her potential energy is at its highest, and her kinetic energy is at its lowest. As Liz swings upward, her potential energy increases (due to her height above the ground) while her kinetic energy decreases (as her speed decreases). So, the correct answer is D - Potential energy is at highest, and kinetic energy is at lowest.

5. When the temperature of an object increases, the kinetic energy of the particles in the object also increases. Temperature is a measure of the average kinetic energy of the particles in an object. As the temperature rises, the particles move faster and their kinetic energy increases. So, the correct answer is B - It increases.

I hope this explanation helps you understand why these answers were chosen. If you have any further questions, feel free to ask!