Explanation:
Speed of the marathon runner, v = 9.51 mi/hr
Distance covered by the runner, d = 26.220 mile
Let t is the time taken by the marathon runner. We know that the speed of the runner is given by total distance divided by total time taken. Mathematically, it is given by :



t = 2.75 hours
Since, 1 hour = 60 minutes
t = 165 minutes
Since, 1 minute = 60 seconds
t = 9900 seconds
Hence, this is the required solution.
Answer:
The conditions necessary for hearing the echo. The distance between the sound source and the reflecting surface must not be less than 17 metres where the time period between hearing the original sound and its echo should not be less than 0.1 of a second.
Answer:
658.16N
Explanation:
Step one:
given data
mass m= 235kg
Force F= 760N
angle= 30 degrees
Required
The horizontal component of the force
Step two:
The horizontal component of the force
Fh= 760cos∅
Fh=760cos30
Fh=760*0.8660
Fh=658.16N
Answer. Explanation: Frequency of the sound decreases and the speed of sound becomes 346m/s from near about 1500 m/s.
1. earth
2. solar system
3. milky way galaxy
4. local group of galaxies
5. universe