Answer:
That is, mechanical waves cannot travel through a vacuum. This feature of mechanical waves is often demonstrated in a Physics class. A ringing bell is placed in a jar and air inside the jar is evacuated. Once air is removed from the jar, the sound of the ringing bell can no longer be heard.
The answer would be slowly
Answer:
Explanation:
a )
hear energy required to melt 1 g of ice = 340 J ,
hear energy required to melt 80 g of ice = 340 x 80 J = 27220 J .
b ) energy gained by the melted ice ( water at O°C ) = m ct
where m is mass of water , s is specific heat and t is rise in temperature
= 80 x 4.2 x ( 8°C - 0°C)
= 2688 J .
c )
energy lost by lime juice = energy gained by ice and water
= 27220 J + 2688 J .
= 29908 J .
d )
Let specific heat required be S
Heat lost by lime juice = M S T
M is mass of lime juice , S is specific heat , T is decrease in temperature
= 320 g x S x ( 29 - 8 )°C
= 6720 S
For equilibrium
Heat lost = heat gained
6720 S = 29908 J
S = 4.45 J /g °C .
Answer:
Mechanical advantage = 4
Explanation:
Given the following data;
Distance of effort, de = 8m
Distance of ramp, dr = 2m
To find the mechanical advantage;
Mechanical advantage = de/dr
Substituting into the equation, we have;
Mechanical advantage = 8/2
Mechanical advantage = 4
Answer:
v = 83.1 % of speed of light
Explanation:
given,
T_e is the earth time = 2.7 s
T_s is the ship time = 1.5 s
we know,

where c is the speed of light
v is the speed of the rock star moving



squaring both side


v = 0.831 c
v = 83.1 % of speed of light