Question
16.The ________ of energy states that in any physical or chemical process, energy is neither created nor destroyed.
A) law of expenditure
B) law of Mrs. Hankinson's power
C) law of conservation
D) law of universal gravitation
17. What would happen to your weight if the force of gravity on Earth decreased?
A) Not enough information
B) It would decrease
C) It would increase
D) It would stay the same
18. Which object has the greatest kinetic energy?
a
a truck with a mass of 3,500 kg moving at 30 m/s
b
a locomotive engine with a mass of 205,000 kg moving 5 m/s
c
a person with a mass of 73 kg running 6 m/s
d
a fast pitched baseball with a mass of .5 kg moving at 46.9 m/s
19. A 1000 kg car traveling with a speed of 29 m/s drives horizontally off of a 100 m cliff. The initial potential energy is _____.
Use g=9.8 m/s2
a
98,000 Nm
b
14,500 J
c
980,000 J
d
420,500 J
A) law of expenditure
B) law of Mrs. Hankinson's power
C) law of conservation
D) law of universal gravitation
17. What would happen to your weight if the force of gravity on Earth decreased?
A) Not enough information
B) It would decrease
C) It would increase
D) It would stay the same
18. Which object has the greatest kinetic energy?
a
a truck with a mass of 3,500 kg moving at 30 m/s
b
a locomotive engine with a mass of 205,000 kg moving 5 m/s
c
a person with a mass of 73 kg running 6 m/s
d
a fast pitched baseball with a mass of .5 kg moving at 46.9 m/s
19. A 1000 kg car traveling with a speed of 29 m/s drives horizontally off of a 100 m cliff. The initial potential energy is _____.
Use g=9.8 m/s2
a
98,000 Nm
b
14,500 J
c
980,000 J
d
420,500 J
Answers
GPT-4o mini
Here are the answers to your questions:
16. The **C) law of conservation** of energy states that in any physical or chemical process, energy is neither created nor destroyed.
17. If the force of gravity on Earth decreased, your weight would **B) It would decrease**. Weight is the force exerted by gravity on an object, so a decrease in gravity would result in a decrease in weight.
18. To find out which object has the greatest kinetic energy (KE), we can use the formula:
\[ KE = \frac{1}{2} mv^2 \]
where \( m \) is the mass and \( v \) is the velocity.
- a) Truck: \( KE = \frac{1}{2} \times 3500 \, \text{kg} \times (30 \, \text{m/s})^2 = \frac{1}{2} \times 3500 \times 900 = 1575000\, \text{J} \)
- b) Locomotive: \( KE = \frac{1}{2} \times 205000 \, \text{kg} \times (5 \, \text{m/s})^2 = \frac{1}{2} \times 205000 \times 25 = 2562500\, \text{J} \)
- c) Person: \( KE = \frac{1}{2} \times 73 \, \text{kg} \times (6 \, \text{m/s})^2 = \frac{1}{2} \times 73 \times 36 = 1314\, \text{J} \)
- d) Baseball: \( KE = \frac{1}{2} \times 0.5 \, \text{kg} \times (46.9 \, \text{m/s})^2 = \frac{1}{2} \times 0.5 \times 2198.61 \approx 549.65\, \text{J} \)
The object with the greatest kinetic energy is **b) a locomotive engine with a mass of 205,000 kg moving at 5 m/s**.
19. To find the initial potential energy (PE) of the car, we can use the formula:
\[ PE = mgh \]
where:
- \( m = 1000 \, \text{kg} \)
- \( g = 9.8 \, \text{m/s}^2 \)
- \( h = 100 \, \text{m} \)
So:
\[ PE = 1000 \, \text{kg} \times 9.8 \, \text{m/s}^2 \times 100 \, \text{m} = 9800000 \, \text{J} \]
Hence, the initial potential energy is **c) 980,000 J**.
16. The **C) law of conservation** of energy states that in any physical or chemical process, energy is neither created nor destroyed.
17. If the force of gravity on Earth decreased, your weight would **B) It would decrease**. Weight is the force exerted by gravity on an object, so a decrease in gravity would result in a decrease in weight.
18. To find out which object has the greatest kinetic energy (KE), we can use the formula:
\[ KE = \frac{1}{2} mv^2 \]
where \( m \) is the mass and \( v \) is the velocity.
- a) Truck: \( KE = \frac{1}{2} \times 3500 \, \text{kg} \times (30 \, \text{m/s})^2 = \frac{1}{2} \times 3500 \times 900 = 1575000\, \text{J} \)
- b) Locomotive: \( KE = \frac{1}{2} \times 205000 \, \text{kg} \times (5 \, \text{m/s})^2 = \frac{1}{2} \times 205000 \times 25 = 2562500\, \text{J} \)
- c) Person: \( KE = \frac{1}{2} \times 73 \, \text{kg} \times (6 \, \text{m/s})^2 = \frac{1}{2} \times 73 \times 36 = 1314\, \text{J} \)
- d) Baseball: \( KE = \frac{1}{2} \times 0.5 \, \text{kg} \times (46.9 \, \text{m/s})^2 = \frac{1}{2} \times 0.5 \times 2198.61 \approx 549.65\, \text{J} \)
The object with the greatest kinetic energy is **b) a locomotive engine with a mass of 205,000 kg moving at 5 m/s**.
19. To find the initial potential energy (PE) of the car, we can use the formula:
\[ PE = mgh \]
where:
- \( m = 1000 \, \text{kg} \)
- \( g = 9.8 \, \text{m/s}^2 \)
- \( h = 100 \, \text{m} \)
So:
\[ PE = 1000 \, \text{kg} \times 9.8 \, \text{m/s}^2 \times 100 \, \text{m} = 9800000 \, \text{J} \]
Hence, the initial potential energy is **c) 980,000 J**.