Answer:
a. wavelength of the sound,
b. observed frequecy,
Given:
speed of sound source, = 80 m/s
speed of sound in air or vacuum, = 343 m/s
speed of sound observed, = 0 m/s
Solution:
From the relation:
v = (1)
where
v = velocity of sound
= observed frequency of sound
= wavelength
(a) The wavelength of the sound between source and the listener is given by:
(2)
(b) The observed frequency is given by:
(3)
Using eqn (2) and (3):
a) An inflated balloon was pressed against a wall after it has been rubbed with a piece of synthetic cloth. It was found that the balloon sticks to the wall. <u>This is because a positive and negative electric charge is produced, therefore the balloon sticks to the wall.</u>
b) When an object is thrown up, it comes back to ground <u>because of gravitational attraction force of earth</u>.
c) Mountaineers suffer nose bleeding at higher altitudes <u>because the oxygen level decreases with increase in altitude, which the body cannot adjust.</u>
d) Foundations of high rise buildings are kept wide <u>because more is the area of contact, less is the pressure efforts. So, foundations are wide so as to decrease the possibility of the building from falling down.</u>
e) Deep sea divers or high altitude fliers wear special suits <u>so as prevent their body from being crushed by the water pressure. Since water pressure is maximum at deep seas and oceans, therefore, more is the risk of being injured.</u>
f) Walls of a dam are thickened near the base <u>so that the dam can handle the kinetic energy pressure and prevent itself from breaking down, which if not, can lead to flooding</u>.
HOPE IT HELPS...
Answer:
20 kg
Explanation:
remember the equation f=ma.
100 N=force
5 m/s2= acceleration
so you need to divide force by acceleration: 100 N/ 5 m/s2= 20 kg, to get the mass.
Acceleration=(change in speed)/(time for the change). 43/0.28 = 153.6 m/s^2.