Sound waves travel faster through <em>solids</em> than they do through gases or liquids. <em>(C) </em>They don't travel through vacuum at all.
Example:
Speed of sound in normal air . . . around 340 m/s
Speed of sound in water . . . around 1,480 m/s
Speed of sound in iron . . . around 5,120 m/s
Answer:
Explanation:
The charges will repel each other and go away with increasing velocity , their kinetic energy coming from their potential energy .
Their potential energy at distance d
= kq₁q₂ / d
= 9 x 10⁹ x 36 x 10⁻¹² / 2 x 10⁻² J
= 16.2 J
Their total kinetic energy will be equal to this potential energy.
2 x 1/2 x mv² = 16.2
= 3 x 10⁻⁶ v² = 16.2
v = 5.4 x 10⁶
v = 2.32 x 10³ m/s
When masses are different , total P.E, will be divided between them as follows
K E of 3 μ = (16.2 / 30+3) x 30
= 14.73 J
1/2 X 3 X 10⁻⁶ v₁² = 14.73
v₁ = 3.13 x 10³
K E of 30 μ = (16.2 / 30+3) x 3
= 1.47 J
1/2 x 30 x 10⁻⁶ x v₂² = 1.47
v₂ = .313 x 10³ m/s
Given data
Power (P) = 50 hp,
= 50 × 746, we know that 1 hp = 746 W.
= 37300 Watts (Watt = J/s)
Work = 6.40 ×10⁴ J
Power is defined as rate of doing work and the unit of power is<em> Watt.</em>
Mathematically,
Power = (Work / time) Watts
= 6.40 ×10⁴ / time
37300 W = 6.40 ×10⁴ J /time (Where time in seconds)
=> time = Work/Power
= 6.40 ×10⁴/37300
= <em>1.74 seconds </em>
<em> </em><em>Therefore , the engine need 1.74 seconds to do 6.40 6.40 ×10⁴ J of work </em>
<em> </em>
The steel traps the heat more making it hotter,you put this twice by the way.
