physics help URGENT!!!
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An artificial satellite of earth releases a bomb. neglecting air resistance, the bomb will:
hit earth under/ahead/behind the satellite or never hit earth at all
a 0.25 KG block oscillates at the end of the spring with a spring constant of 200N/m . if the oscillation is started by elongating the spring 0.15m and giving the block a speed of 3.0 m/s, the max speed of the block is?
which statement is incorrect for a transverse wave traveling on a string?
aThe energy of the wave is proportional to the square of the waves amplitude
bThe speed of a moving point on the string is the same as the wave speed
cThe speed of the wave increase with frequency and wavelength of the waves
dAll the particles on the string vibrate with the same frequency. -
bump!!!!!!!!!!
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Stooo-pid questions leh.... I want better questions before I answer!
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i think never hit if i remember correctly. assuming release is just let go.Originally posted by unclebutcher:An artificial satellite of earth releases a bomb. neglecting air resistance, the bomb will:
hit earth under/ahead/behind the satellite or never hit earth at all
a 0.25 KG block oscillates at the end of the spring with a spring constant of 200N/m . if the oscillation is started by elongating the spring 0.15m and giving the block a speed of 3.0 m/s, the max speed of the block is?
which statement is incorrect for a transverse wave traveling on a string?
aThe energy of the wave is proportional to the square of the waves amplitude
bThe speed of a moving point on the string is the same as the wave speed
cThe speed of the wave increase with frequency and wavelength of the waves
dAll the particles on the string vibrate with the same frequency.
erm i forgot the equatin. but i think F= kx so can find the force then can find initial acceleration due to F= ma. having boundary conditions that t= 0 v = 3 i think can find max speed.
forgot whats a transverse wave -
uncle u solved already a not? I just realised I missed out seeing this question yesterday
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haha actually no....can help? thanks.Originally posted by eagle:uncle u solved already a not? I just realised I missed out seeing this question yesterday -
Geostationary?Originally posted by unclebutcher:An artificial satellite of earth releases a bomb. neglecting air resistance, the bomb will:
hit earth under/ahead/behind the satellite or never hit earth at all
I dunno if your spring is hanging down or horizontal. I shall assume it as horizontal for easier calculationsOriginally posted by unclebutcher:a 0.25 KG block oscillates at the end of the spring with a spring constant of 200N/m . if the oscillation is started by elongating the spring 0.15m and giving the block a speed of 3.0 m/s, the max speed of the block is?
energy stored by spring at extension of 0.15m = 1/2 * 200 * 0.15^2 = 2.25J
Max speed at 0 extension
using conservation of energy
1/2 m v^2 = 2.25J + 1/2 m 3^2
v = sqrt(27) m/s
not sure about this...
B is wrong because the speed of the moving point varies whereas the wave speed is a constant. The point moves perpendicular to the direction of the wave.Originally posted by unclebutcher:which statement is incorrect for a transverse wave traveling on a string?
aThe energy of the wave is proportional to the square of the waves amplitude
bThe speed of a moving point on the string is the same as the wave speed
cThe speed of the wave increase with frequency and wavelength of the waves
dAll the particles on the string vibrate with the same frequency. -
Originally posted by eagle:
how come got extra 1/2?
I dunno if your spring is hanging down or horizontal. I shall assume it as horizontal for easier calculations
energy stored by spring at extension of 0.15m = 1/2 * 200 * 0.15^2 = 2.25J
Max speed at 0 extension
using conservation of energy
1/2 m v^2 = 2.25J + 1/2 m 3^2
v = sqrt(27) m/s
not sure about this... -
By conservation of energy,
½mv²=½kx²+½mu²
v²=kx²/m+u²
= [(200N/m)(0.15m)²]/(0.25kg) + (3.0m/s)²
= 27m²/s²
v=3*sqrt(3) m/s -
Energy stored in spring is 1/2 k e^2 right?Originally posted by unclebutcher:how come got extra 1/2? -
oh yeah i forgot liaoOriginally posted by eagle:Energy stored in spring is 1/2 k e^2 right?