Physics worksheet on energy concepts, including kinetic and potential energy, with student answers and calculations.

Let’s go through each problem step by step.

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Problem 1: Identify KE, PE, or B

We need to match each statement with Kinetic Energy (KE), Potential Energy (PE), or Both (B).

1. “If an object is at rest, it certainly does NOT possess this form of energy.”
→ If it’s not moving, it has no kinetic energy. So this is KE.

2. “Depends upon object mass and object height.”
→ Height relates to gravitational potential energy. So this is PE.

3. “The energy an object possesses due to its motion.”
→ That’s the definition of kinetic energy. So KE.

4. “The amount is expressed using the unit joule (abbreviated J).”
→ Both KE and PE are measured in joules. So B.

5. “The energy stored in an object due to its position (or height).”
→ That’s potential energy. So PE.

6. “The amount depends upon the arbitrarily assigned zero level.”
→ Only potential energy depends on where you set “zero height.” So PE.

7. “Depends upon object mass and object speed.”
→ Speed is for kinetic energy. So KE.

8. “If an object is at rest on the ground (zero height), it certainly does NOT possess this form of energy.”
→ At rest → no KE; on ground → no PE. But the statement says “this form” — meaning one specific type. Since it mentions both conditions (rest AND ground), but the key is that if it’s on the ground, it has no PE — so this refers to PE? Wait — let’s think again.

Actually, re-reading: “If an object is at rest on the ground... it certainly does NOT possess this form of energy.”

But if it’s at rest, it has no KE. If it’s on the ground, it has no PE. So which one is being referred to?

Look at #1: same idea but only “at rest” → KE.

Here, it adds “on the ground” — so now it’s also eliminating PE? But the question asks for “this form” — singular.

Actually, look at the answer given in the image: it says B for #8. Why?

Because if an object is at rest AND on the ground, it has neither KE nor PE — so it doesn’t possess either form. But the statement says “this form” — implying one. Hmm.

Wait — maybe the trick is: if it’s on the ground, it has no PE — regardless of motion. But if it’s at rest, it has no KE. So if BOTH are true, then it has neither. But the question is asking which form it does NOT possess — and since it possesses neither, perhaps they mean “both forms”? But the options are KE, PE, or B (both).

Actually, looking back at the student’s answers in the image, they put B for #8 — and that makes sense because if an object is at rest on the ground, it has zero KE and zero PE — so it doesn’t possess either form. Therefore, the correct label is B — meaning both forms are absent.

So we’ll go with that.

Final answers for #1:
1. KE
2. PE
3. KE
4. B
5. PE
6. PE
7. KE
8. B

*(Note: The student’s handwritten answers match these.)*

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Problem 2:

A toy car has 0.40 J of KE. If speed is doubled, what’s new KE?

Kinetic energy formula:
KE = ½ mv²

If speed doubles → v becomes 2v → v² becomes (2v)² = 4v² → KE becomes 4 times bigger.

Original KE = 0.40 J
New KE = 4 × 0.40 = 1.60 J

Answer: d. 1.60 J

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Problem 3:

Glider has 0.80 J of PE. Speed doubled, height doubled → new PE?

Potential energy (gravitational): PE = mgh

It depends on mass, gravity, and height — NOT speed.

So doubling speed does NOTHING to PE.

Doubling height → PE doubles.

Original PE = 0.80 J
New PE = 2 × 0.80 = 1.60 J

Answer: c. 1.60 J

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Problem 4:

Which is ALWAYS true if KE = 0 joules?

KE = ½ mv² → if KE = 0, then either m=0 (not possible for real objects) or v=0 → object is at rest.

So always true: b. It is at rest

Other options: could be on ground? Not necessarily — could be high up but not moving. Could be accelerating? No — if accelerating, speed is changing, but if KE=0, speed must be 0 — so not accelerating unless starting from rest, but even then, at that instant, it’s at rest.

Best answer: b. It is at rest

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Problem 5:

Which is ALWAYS true if PE = 0 joules?

PE = mgh → if PE = 0, then either m=0 (no), g=0 (no), or h=0 → height is zero → on the ground (assuming ground is our reference point).

So always true: a. It is on the ground

Note: We assume “ground” means the reference level where h=0. In physics problems, when we say PE=0, we usually mean relative to a chosen zero point — often the ground.

So answer: a. It is on the ground

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Problem 6:

Calculate KE of 5.2 kg object moving at 2.4 m/s.

Formula: KE = ½ mv²

m = 5.2 kg
v = 2.4 m/s
v² = 2.4 × 2.4 = 5.76

KE = 0.5 × 5.2 × 5.76

First: 0.5 × 5.2 = 2.6
Then: 2.6 × 5.76

Let’s compute:

2.6 × 5 = 13
2.6 × 0.76 = ?

2.6 × 0.7 = 1.82
2.6 × 0.06 = 0.156
Total = 1.82 + 0.156 = 1.976

So total KE = 13 + 1.976 = 14.976 J

Round to reasonable digits: inputs have 2 sig figs? 5.2 (2), 2.4 (2) → so answer should have 2 sig figs? But 5.2 and 2.4 both have 2, but multiplication: actually, 5.2 × 2.4² → 2.4² = 5.76 (3 sig figs?), but better to follow calculation.

In the student’s work, they got 14.97 J — which is fine. Let’s keep it as 15.0 J if rounding to 3 sig figs, but original numbers: 5.2 (2 sig figs), 2.4 (2 sig figs) → product should have 2 sig figs → 15 J.

But let’s check exact:

½ × 5.2 × (2.4)^2 = 0.5 × 5.2 × 5.76 = 2.6 × 5.76

2.6 × 5.76:

Do 26 × 576 = ? Better:

2.6 × 5.76 = 2.6 × (5 + 0.76) = 2.6×5 = 13, 2.6×0.76:

0.76 × 2.6:

76 × 26 = 1976 → move decimal 3 places → 1.976

Total: 13 + 1.976 = 14.976 ≈ 15.0 J (if we take 3 sig figs) or 15 J (2 sig figs).

But in the student’s answer, they wrote 14.97 J — probably acceptable. I’ll go with 15.0 J for clarity.

Actually, let’s calculate precisely:

5.2 × 5.76 = ?

5 × 5.76 = 28.8
0.2 × 5.76 = 1.152
Total = 29.952
Then half of that? No — wait, KE = ½ mv² = 0.5 × m × v²

So 0.5 × 5.2 × 5.76 = first 5.2 × 5.76 = let's do:

5.2 × 5 = 26
5.2 × 0.76 = 5.2 × 0.7 = 3.64, 5.2 × 0.06 = 0.312 → total 3.952
So 26 + 3.952 = 29.952
Then × 0.5 = 14.976 J

Yes, 14.976 J — typically rounded to 15.0 J or kept as 15 J.

But since the problem says "PSYW" (probably "show your work"), and student wrote 14.97, we can say 15.0 J.

I'll use 15.0 J.

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Problem 7:

Calculate PE of 5.2 kg object at 5.8 m above ground.

PE = mgh

g = 9.8 m/s² (usually, unless specified otherwise — student used 10, but let's use 9.8 for accuracy)

m = 5.2 kg
g = 9.8 m/s²
h = 5.8 m

PE = 5.2 × 9.8 × 5.8

First, 5.2 × 9.8:

5 × 9.8 = 49
0.2 × 9.8 = 1.96
Total = 50.96

Then 50.96 × 5.8

50.96 × 5 = 254.8
50.96 × 0.8 = 40.768
Total = 254.8 + 40.768 = 295.568 J

≈ 296 J (rounded to 3 sig figs)

But student used g=10:

5.2 × 10 × 5.8 = 52 × 5.8 = 50×5.8=290, 2×5.8=11.6 → 301.6 J

Since the problem didn't specify g, and student used 10, perhaps it's acceptable. But standard is 9.8.

However, in many school problems, they use g=10 for simplicity. Looking at the student’s answer: 301.6 J — so they used g=10.

To match common practice in such worksheets, I’ll go with g = 10 m/s² as implied by the student’s work.

So PE = 5.2 × 10 × 5.8 = 52 × 5.8

52 × 5 = 260
52 × 0.8 = 41.6
Total = 301.6 J

Answer: 301.6 J

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Problem 8:

Calculate speed of 5.2 kg object with 26.1 J of KE.

KE = ½ mv²

So 26.1 = 0.5 × 5.2 × v²

First, 0.5 × 5.2 = 2.6

So 26.1 = 2.6 × v²

Then v² = 26.1 / 2.6

Calculate: 26.1 ÷ 2.6

2.6 × 10 = 26 → so 26.1 / 2.6 = 10.03846...

v² ≈ 10.0385

v = √10.0385 ≈ ?

√9 = 3, √16=4, √10.24=3.2, since 3.2²=10.24

10.0385 is less than 10.24 → try 3.17

3.17² = 3.17 × 3.17

3×3=9, 3×0.17=0.51 doubled is 1.02, plus 0.17²=0.0289 → total 9 + 1.02 + 0.0289 = 10.0489 → close to 10.0385

Try 3.168

3.168² = ?

Approximately 3.17 is fine.

More accurately:

26.1 / 2.6 = 261 / 26 = 10.0384615...

√10.0384615 ≈ 3.1685

So v ≈ 3.17 m/s

Check: ½ × 5.2 × (3.17)^2 = 2.6 × 10.0489 ≈ 26.127 → very close to 26.1

So 3.17 m/s

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Now, compiling all final answers:

For Problem 1:
1. KE
2. PE
3. KE
4. B
5. PE
6. PE
7. KE
8. B

Problem 2: d. 1.60 J
Problem 3: c. 1.60 J
Problem 4: b. It is at rest
Problem 5: a. It is on the ground
Problem 6: 15.0 J (or 14.98 J, but 15.0 is fine)
Problem 7: 301.6 J (using g=10)
Problem 8: 3.17 m/s

But since the user might expect exact matches to typical expectations, and for Problem 6, let's use the precise value.

Actually, for consistency, I'll present as calculated.

Final Answer:

1. KE, PE, KE, B, PE, PE, KE, B
2. d
3. c
4. b
5. a
6. 15.0 J
7. 301.6 J
8. 3.17 m/s

But to box them properly.

Since it's multiple parts, I'll list them clearly.

Final Answer:
1. 1. KE, 2. PE, 3. KE, 4. B, 5. PE, 6. PE, 7. KE, 8. B
2. d
3. c
4. b
5. a
6. 15.0 J
7. 301.6 J
8. 3.17 m/s