Answer:
Explanation:
mass of the ball = 146 g = 146 / 1000 = 0.146 kg
initial speed of the ball = 40.6 m/s
final speed of the ball = - 45.1 m/s
time of impact = 1.05 ms = 1.05 / 1000 = 0.00105 s
impulse, Ft = change in momentum = mv - mu = m (v-u)
F = m (v - u) / t = 0.146 kg ( -45.1 -40.6) / 0.00105 s = -11916.4 N
Answer:
E = 3456 J
Explanation:
The electrical energy expended in a resistor can be easily calculated by using the following formula:
where,
E = Energy Expended = ?
I = current through 5 ohm resistor = 2.4 A
R = Resistance = 5 ohms
P = Electrical Power = VI
Since,
V = IR (Ohm's Law)
Therefore,
P = (IR)(I) = I²R = (2.4 A)²(5 ohms) = 28.8 Watt
t = time taken = (2 min)(60 s/1 min) = 120 s
Therefore,
E = (28.8 Watt)(120 s)
<u>E = 3456 J</u>
Answer is C. Kelvin, Kelvin is the temperature scales does water boil at the highest numerical value. Hope it helped you, and have a great day.
-Charlie
Answer:
<em>d. The sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.</em>
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Explanation:
Let us take the momentum of a photon unit as u
we know that the rate of change of momentum is proportional to the force exerted.
For a absorbing surface, the photon is absorbed, therefore the final momentum is zero. From this we can say that
F = (u - 0)/t = u/t
for a unit time, the force is proportional to the momentum of the wave due to its energy density. Therefore,
F = u
For a reflecting surface, the momentum of the wave strikes the sail and changes direction. Since we know that the speed of light does not change, then the force is proportional to
F = (u - (-u))/t = 2u/t
just as the we did above, it becomes
F = 2u.
From this we can see that the force for a reflective sail is twice of that for an absorbing sail, and we know that the pressure is proportional to the force for a given area. From these, we conclude that <em>the sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.</em>
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