<u>Answer</u>
2.06977 seconds
<u>Explanation</u>
Acceleration, a, is the rate of change of velocity
a = (v-u)/t
where v and u are final and initial velocities respectively.
4.3 = (16.0 - 7.1)/t
4.3 = 8.9/t
t = 8.9/4.3
= 2.06977 seconds
Answer:
512.5 mJ
Explanation:
Let the two identical charges be q = +35 µC and distance between them be r₁ = 46 cm. A charge q' = +0.50 µC located mid-point between them is at r₂ = 46 cm/2 = 23 cm = 0.23 m.
The electric potential at this point due to the two charges q is thus
V = kq/r₂ + kq/r₂
= 2kq/r₂
= 2 × 9 × 10⁹ Nm²/C² × 35 × 10⁻⁶ C/0.23 m
= 630/0.23 × 10³ V
= 2739.13 × 10³ V
= 2.739 MV
When the charge q' is moved 12 cm closer to either of the two charges, its distance from each charge is now r₃ = r₂ + 12 cm = 23 cm + 12 = 35 cm = 0.35 m and r₄ = r₂ - 12 cm = 23 cm - 12 cm = 11 cm = 0.11 cm.
So, the new electric potential at this point is
V' = kq/r₃ + kq/r₄
= kq(1/r₃ + 1/r₄)
= 9 × 10⁹ Nm²/C² × 35 × 10⁻⁶ C(1/0.35 m + 1/0.11 m)
= 315 × 10³(2.857 + 9.091) V
= 315 × 10³ (11.948) V
= 3763.62 × 10³ V
= 3.764 MV
Now, the work done in moving the charge q' to the point 12 cm from either charge is
W = q'(V' - V)
= 0.5 × 10⁻⁶ C(3.764 MV - 2.739 MV)
= 0.5 × 10⁻⁶ C(1.025 × 10⁶) V
= 0.5125 J
= 512.5 mJ
Heat required to decrease the temperature of body is given as

here given that



now by above equation


now in order to evaporate water the heat is given as




so 97 g of water will evaporate from the body
<span>Rays will follow the law of reflection, so the angle of reflection will be 35 degrees. If a</span> light ray strikes a smooth surface, the reflected ray will bounce off the surface with the same angle the ray hits the surface. In other words, the angle of incidence is the same of angle of reflection, which is 35 degrees. If the surface is not smooth, the reflected ray might diffuse in all directions.