Question

Question 23
If a 35 kg zombie runs at a speed of 3.0 m/s. What is the zombie's kinetic energy?



a
158 J
b
315 J
c
53 J
d
105 J
Question 24
Mrs. Wade puts a bucket of paint on top of a ladder. The bucket has a mass of 20 kg. The top of the ladder is 5 meters tall. How much potential energy does the bucket have?



a
980 J
b
cannot be determined
c
100 J
d
40 J

Answer 1

To calculate the kinetic energy and potential energy, we can use the following formulas:

1. **Kinetic Energy (KE)**:
\[
KE = \frac{1}{2} m v^2
\]
where \( m \) is the mass in kilograms and \( v \) is the velocity in meters per second.

2. **Potential Energy (PE)**:
\[
PE = mgh
\]
where \( m \) is the mass in kilograms, \( g \) is the acceleration due to gravity (approximately \( 9.8 \, \text{m/s}^2 \)), and \( h \) is the height in meters.

### Question 23:
Given:
- Mass of the zombie \( m = 35 \, \text{kg} \)
- Speed of the zombie \( v = 3.0 \, \text{m/s} \)

Substituting into the kinetic energy formula:
\[
KE = \frac{1}{2} (35 \, \text{kg}) (3.0 \, \text{m/s})^2
\]
\[
KE = \frac{1}{2} (35) (9) = \frac{1}{2} \times 315 = 157.5 \, \text{J} \approx 158 \, \text{J}
\]

So, the answer is **a) 158 J**.

### Question 24:
Given:
- Mass of the bucket \( m = 20 \, \text{kg} \)
- Height \( h = 5 \, \text{m} \)
- Acceleration due to gravity \( g = 9.8 \, \text{m/s}^2 \)

Substituting into the potential energy formula:
\[
PE = (20 \, \text{kg}) (9.8 \, \text{m/s}^2) (5 \, \text{m})
\]
\[
PE = 20 \times 9.8 \times 5 = 980 \, \text{J}
\]

So, the answer is **a) 980 J**.