The answer is D because instantaneous means at a particular point in time
Answer:
14 cm
Explanation:
F = (frac{uv}{u – v})
F = +ve
v = -ve
30 = (frac {25 {times} (-v)}{25 – (-v)})
v = (frac {25 {times} (-v)}{25+v})
v = 14cm
(Note that either negative or positive values go to show the positioning and hence, they are not a strong necessity in your final answer.)
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Answer:
3. both are true.
Explanation:
Energy increses with decrease in wavelenght.
For photoemission to occur, a threshold energy barrier must be broken.
Higher energy means more electrons will be emmited.
The electrons emmited will posses energy that is less than the incident energy by the value of the threshold energy.
So the higher the energy, the higher the energy possessed by the electrons.
Answer:
Explanation:
The angular position of first intensity maxima is given by the expression
= λ / d where λ is wave length of light and d is slit separation
putting the values given in the problem. ,
.02 = λ₁ / D
Now wavelength has been increased to 2λ₁
angular separation of first maxima
= 2λ₁ /D
= 2 x .02
= .04 radians.
Answer:
1.25 m/s
Explanation:
Given,
Mass of first ball=0.3 kg
Its speed before collision=2.5 m/s
Its speed after collision=2 m/s
Mass of second ball=0.6 kg
Momentum of 1st ball=mass of the ball*velocity
=0.3kg*2.5m/s
=0.75 kg m/s
Momentum of 2nd ball=mass of the ball*velocity
=0.6 kg*velocity of 2nd ball
Since the first ball undergoes head on collision with the second ball,
momentum of first ball=momentum of second ball
0.75 kg m/s=0.6 kg*velocity of 2nd ball
Velocity of 2nd ball=0.75 kg m/s ÷ 0.6 kg
=1.25 m/s