If you are pushing the coin across the table at a constant rate, the friction of the table and the horizontal force of your hand pushing are equal, and the coin itself moves at a constant rate. If you push a coin and let it go, there is no horizontal force keeping the coin going. Friction slows the coin to a stop. In both cases, the gravitational downward pull of Earth is equally but oppositely resisted by the upward push of table on the coin.
Option (b) is correct.The index of refraction for the glass is 1.52
Explanation:
velocity of light in vacuum= C= 2.99 x 10⁸m/s
Velocity of light in glass = V= 1.97 x 10⁸m/s
The refractive index is given by n=
n= 2.99 x 10⁸/1.97 x 10⁸m/s
n= 1.52
Thus the refractive index of glass is 1.52
Answer: 846°C
Explanation:
The quantity of Heat Energy (Q) required to heat bismuth depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Given that:
Q = 423 joules
Mass of bismuth = 4.06g
C = 0.123 J/(g°C)
Φ = ?
Then, Q = MCΦ
423 J = 4.06g x 0.123 J/(g°C) x Φ
423 J = 0.5J/°C x Φ
Φ = (423J/ 0.5g°C)
Φ = 846°C
Thus, the change in temperature of the sample is 846°C
The second runner must run 3.3m/s. If the leading runner is 1.5 seconds ahead and there are 30m left, the second runner would need to run slightly faster than the lead in order to finish at the same time. To calculate this I did 30/1.5 which gave me 0.05. I added this onto the speed of the lead runner to get 3.3m/s :)
