Hi there!
Acceleration = change in velocity / change in time = Δv/Δt
Thus:
a = (75 - 15)/4 = 60/4 = 15 mi/hr²
The gravitational potential energy will increase by 423.36 J
<h3>How to determine the potential energy at ground level</h3>
- Mass (m) = 72 kg
- Acceleration due to gravity (g) = 9.8 m/s²
- Height (h) = 0 m
- Potential energy at ground level (PE₁) =?
PE = mgh
PE₁ = 72 × 9.8 × 0
PE₁ = 0 J
<h3>How to determine the potential energy at 60 cm (0.6 m)</h3>
- Mass (m) = 72 kg
- Acceleration due to gravity (g) = 9.8 m/s²
- Height (h) = 0.6 m
- Potential energy at 60 cm (0.6 m) (PE₂) =?
PE = mgh
PE₂ = 72 × 9.8 × 0.6
PE₂= 423.36 J
<h3>How to determine the change in potential energy </h3>
- Potential energy at ground level (PE₁) = 0 J
- Potential energy at 60 cm (0.6 m) (PE₂) = 423.36 J
- Change in potential energy =?
Change in potential energy = PE₂ - PE₁
Change in potential energy = 423.36 - 0
Change in potential energy = 423.36 J
Learn more about energy:
brainly.com/question/10703928
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Distance travelled in south direction= 1.5hr*0.75km/hr= 1.125km
Distance travlled in north direction= 0.90*2.5=2.25
Net displacement = 2.25-1.125= 1.125 to the north
Answer: #4
Sally is faster.
Explanation:
If you multiply Sallies it is going to be less than Jessica's.
