V^2-u^2=2as
v=final velocity=unkown
u=initial velocity=0 m/s, because freely falling
a=acceleration due to gravity=9.8 m/s^2
s=distance (here height) traveled=4.5m
therefore the final velocity,
v^2=2*9.8*4.5
v=<span>9.39m/s</span>
Answer:
A. Using
Fl= ( v+vl/v+vz)fz
= (340+19/340+31) x 2020
= 1954.7Hz
Then to find the frequency of sound when reflected from the truck such that the driver becomes the listener
we use
F"= ( v+vz/v+vl) fz
= 340+31/340+19 x 2020
2087.5Hz
B to find the wavelength of sound we use
Wavelength= V+vl/ F"
= 340+31/2087.5= 0.18m
A. Golf ball because it has the most mass and will travel faster when felling
Answer:
8977.7 kg/m^3
Explanation:
Volume of water displaced = 55 cm^3 = 55 x 10^-6 m^3
Reading of balance when block is immersed in water = 4.3 N
According to the Archimedes principle, when a body is immersed n a liquid partly or wholly, then there is a loss in the weight of body which is called upthrust or buoyant force. this buoyant force is equal to the weight of liquid displaced by the body.
Buoyant force = weight of the water displaced by the block
Buoyant force = Volume of water displaced x density of water x g
= 55 x 10^-6 x 1000 x .8 = 0.539 N
True weight of the body = Weight of body in water + buoyant force
m g = 4.3 + 0.539 = 4.839
m = 0.4937 kg
Density of block = mass of block / volume of block
=
Density of block = 8977.7 kg/m^3