1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
larisa86 [58]
3 years ago
6

A biker goes up hill with a constant speed of 10km/h. Then he goes downhill with a constant speed of 50km/h. What's his average

speed
Physics
1 answer:
Sladkaya [172]3 years ago
4 0

This is not as simple as it looks.  

His average speed is NOT (10km/hr + 50km/hr)/2 = 30 km/hr.

You have to use the definition of speed:

Speed = (total distance covered) / (time to cover the distance).

Let's say the distance up (and down) the hill is 'd' .

Then the time it takes to go up the hill is (d/10) hours.

And the time it takes to come down the hill is (d/50) hours.

Total distance = 2d km

Total time = (d/10) + (d/50) = (5d/50) + (d/50) = 6d/50

Speed = distance/time = 2d/(6d/50) = 100d/6d

<em>Speed = </em>100/6 = <em>16-2/3 km/hr</em>

You might be interested in
If Earth were twice as far from the sun, the force of gravity attracting the Earth to the Sun would be
posledela
One quater as your moving away more!
3 0
3 years ago
How is sound detected by the brain
ivann1987 [24]

begin with vibrations of the eardrum. Sound waves cause the eardrum to vibrate. Cells in the cochlea detect the vibrations and send a message to the brain.

3 0
3 years ago
Read 2 more answers
A 5.00 kilogram mass is traveling at 100. meters per second. Determine the speed of the mass after an impulse with a magnitude o
faltersainse [42]

m = mass = 5 kg

v_{i} = initial velocity = 100 m/s

v_{f} = final velocity = ?

I = impulse = 30 Ns

Using the impulse-change in momentum equation

I = m(v_{f} - v_{i})

30 = 5 (v_{f} - 100)

v_{f} = 106 m/s

5 0
3 years ago
Read 2 more answers
HELP DUE IN 5 How does a battery supply energy to a circuit?
Gnoma [55]

Answer: It's C

Explanation:

3 0
2 years ago
A 200 N trash can is pulled across the sidewalk by a person at constant speed by a force of 75 N. What is the coefficient of fri
Pavel [41]

Answer:

μ = 0.375

Explanation:

F = Applied force on the trash can = 75 N

W = weight of the trash can = 200 N

f = frictional force acting on trash can

Since the trash can moves at constant speed, force equation for the motion of can is given as

F - f = 0

75 - f = 0

f = 75 N

μ = Coefficient of friction

frictional force is given as

f = μ W

75 = μ (200)

μ = 0.375

5 0
3 years ago
Other questions:
  • If a set of displacement vectors laid head to tail make a closed polygon, what is the resultant vector?
    8·1 answer
  • Plz help
    12·1 answer
  • Spheres of Charge: A metal sphere of radius 10 cm carries an excess charge of +2.0 μC. What is the magnitude of the electric fie
    13·1 answer
  • A 0.358 kg particle slides around a horizontal track. The track has a smooth, vertical outer wall forming a circle with a radius
    14·1 answer
  • What gives an object gravity?
    11·1 answer
  • A 205 kg log is pulled up a ramp by means of a rope that
    12·1 answer
  • An ocean wave energy device moves up and down with the motion of an ocean wave. The device produces more energy if larger waves
    13·1 answer
  • What can you conclude about the velocity of the object on the graph below
    6·1 answer
  • Lab: Waves and Diffraction<br> Assignment: Lab Report<br> Anyone have this completed
    6·1 answer
  • Is chocolate melting in your hand conduction, convection, or radiation?
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!