Echo: This is the sound heard after the reflection of sound wave in a plain surface.
v = 2x/t................................ Equation 1
Where v = velocity of sound in air, x = distance between the mountain and the hikers, t = time to hear the echo.
making x the subject of the equation,
x = vt/2........................... Equation 2
Given: v = 341 m/s, t = 2.9 s.
Substitute into equation 2
x = 341(2.9)/2
x = 494.45 m.
Hence the mountain is 494.45 m far away
A bus travels 300 km south along a straight path with an average velocity of 85 km/h to the south. The bus stops for 22 minutes. Then it travels 220 km south with an average velocity of 78 km/h to the south. How long does the total trip last? What is the average velocity for the total trip?
= 6.72 hours
Explanation and solution;
velocity = distance over time
Since we know the velocity and the distance, we can simply calculate time
For the first part
85 km/h = 300km / time
time = 3.53 hours
Then there is a 22 min stop, which is the same as 0.37 hours
so far the trip is:
3.53 + 0.37 = 3.9 hours
then for the last stretch:
78 km/h = 220 km / time
time = 2.82 hours
So the total trip is:
3.9 + 2.82 = 6.72 hours
= 77.38 km/hr
Explanation and solution;
we take the total distance divided by the total time to get the average.
total distance = 300 km + 220 km = 520 km
total time = 6.72 hours
Average velocity = 520 km / 6.72 hours = 77.38 km/hr
which is an example of action reaction forces?A)a deep space probe drifting in a straight path B)a tennis racket striking a tennis ball C)an air hockey puck moving at a constant speed
Elaborate on the reason(s) that matter is said to move even as in a solid state. A) The particles are bound through intermolecular forces but are able to move past each other with relative freedom.
B) The particles have sufficient energy to become an ionized gas and are in the most common state of matter in the universe.
C) The particles are not able to move out of their positions relative to one another, but do have small vibrational movements.
D) The particles are not bound to one another, move quickly, have a low density, and are able to spread apart from one another if unconstrained.
Brad and Matt are working in the lab. They noticed that when they mixed two dilute solutions together, the reaction between them happened very slowly. Which of Matt's suggestions would BEST help to increase the rate of this reaction?
A) increase the concentration of both solutions
B) decrease the concentration of both solutions
C) increase the concentration of one of the solutions
D) decrease the concentration of one of the solutions
Identify the correct order of increasing intermolecular force of attraction for the three most common states of matter.
A) liquid → solid → gas
B) solid → liquid → gas
C) gas → liquid → solid
D) gas → solid → liquid
On Earth, when a body is in motion, there is always __________ to oppose the motion. a. friction c. gravity b. inertia d. acceleration Please select the best answer from the choices provided
When a body is in motion given Newtons first law it will move in straight line with constant velocity unless acted on by a nonzero net force. Friction is most often this force.
The bullet starts at rest in the gun. An 8.6 g bullet leaves the muzzle of a rifle with a speed of 430.1 m/s. What constant force is exerted on the bullet while it is traveling down the 0.5 m length of the barrel of the rifle?
The constant force exerted on the bullet is 1590.87 N.
It is given that,
Mass of the bullet, m = 8.6 g
Initial speed of the bullet, u = 0
Final speed of the bullet, v = 430.1 m/s
We need to find the force exerted on the bullet while it is traveling down the 0.5 m length of the barrel of the rifle. Let a is the acceleration of the bullet. So,
Let F is the force exerted. It is given by :
F = 1590.87 N
So, the constant force exerted on the bullet is 1590.87 N. Hence, this is the required solution.
The older, geocentric model of the solar system placed the__________ at the center. Today's heliocentric model places the________ at the center of the solar system.
The heliocentric model opposes the geocentric model by placing the sun at the center of the solar system as opposed to the earth as it is with the geocentric model
Which two phases of the water cycle are repeated in this process? A. evaporation and precipitation B. evaporation and condensation C. precipitation and transpiration D. condensation and precipitation
a evaporation, condensation, precipitation
Predicting How would the slope of the graph change if the cyclist
were accelerating at a greater
rate? At a lesser rate?
The slope of the acceleration vs. force graph represents the reciprocal of the mass of the system.
should your directions to a friend for traveling from one city to another include displacements or distances?Explain