Jane's brother Andrew leaves home for school at 8:00 am. He walks at 4.2 kph . At 8:20 am Jane discovers that Andrew has left his homework at home. She decides to follow him on her bicycle and give him his homework, but she wants to be back home in time for an online test at 9:00 am. What is the minimum constant speed at which she needs to ride? (Hint: At what time of day will they meet?) Jane must ride at least \( \qquad \) kph. Enter answer here
Added by Richard G.
Close
Step 1
- Andrew leaves at 8:00 am and walks for 20 minutes (or \( \frac{1}{3} \) hour). - His speed is 4.2 kph. - Distance traveled by Andrew = Speed × Time = \( 4.2 \, \text{kph} \times \frac{1}{3} \, \text{hour} = 1.4 \, \text{km} \). Show more…
Show all steps
Your feedback will help us improve your experience
Ashar Tanveer and 69 other Physics 101 Mechanics educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
For question 2 find the equation needed to solve the problem. Do not solve. 2. a) To bike messengers Jerry and Susan right in opposite directions. If Jerry rides at the rate of 20 km/h, at what rate must Susan ride if they are 150 km apart in five hours. b) A passenger and a freight train start towards each other at the same time from two points 300 km apart. If the rate of the passenger train exceeds the rate of the freight train by 15 km/h and they meet after four hours what must the rate of each be? c) To automobiles start travelling in opposite directions at the same time from the same point. Their rates were 25 and 35 km/h respectively. After how many hours were they 180 km a part? d) A man having 10 hours at his disposal made an excursion by bike, riding out at the rate of 10 km/h and returning on foot at the rate of 3 km/h find the distance he road.
Supreeta N.
Exercise. Huan jogs and walks to school each day. She averages $4 \mathrm{km} / \mathrm{h}$ walking and $8 \mathrm{km} / \mathrm{h}$ jogging. From home to school is $6 \mathrm{km}$ and Huan makes the trip in 1 hr. How far does she jog in a trip?
Systems of Linear Equations and Problem Solving
Solving Applications Systems of Two Equations
Jeff bicycles 120 miles at the rate of r mph. The same trip would have taken 8 hours longer if he had decreased his speed by 4 mph. Find r (in mph). His original speed was r = mph.
Matthew E.
Recommended Textbooks
University Physics with Modern Physics
Physics: Principles with Applications
Fundamentals of Physics
Watch the video solution with this free unlock.
EMAIL
PASSWORD