A=pi r^2
A=( 3.14159.......)(12.77)^2
A= 512.30m^2
4. KE increases by a factor of 16 is the answer
<u>Explanation:</u>
Kinetic energy = (1/2)mv² = 0.5 mv²
where
m = mass, and v = velocity.
So at 15 mph,
K
E = 0.5 m (15)
² = 112.5 m
And at 60 mph,
K
E = 0.5 m (60)² = 1800 m
m is the mass, and not meters.
So, 1800 m/112. 5 m = 16
16 times the Kinetic Energy.
Answer:
B
Explanation:
I think this one is correct
Answer:
(a) = 3.7 × 10⁻⁵
(b) = 4.1 × 10⁻⁶ N.M²/C
Explanation:
(a) Diameter of the sphere, d = 1.2 m
Radius of the sphere, r = 0.6 m
Surface charge density, = 8.1 mC/m2 = 8.1 × 10⁻⁶ C/m²
Total charge on the surface of the sphere,
Q = Charge density × Surface area
= 4πr²σ
= 4 (3.14) (0.12²) (8.1 × 10⁻⁶)
= 3.66 × 10⁻⁵C
≅ 3.7 × 10⁻⁵C
Therefore, the net charge on the sphere is 3.7 × 10⁻⁵C
(b)
Total electric flux (∅)
=Q / ε₀
ε₀ = 8.854 × 10⁻¹² N⁻¹C² m⁻²
Q = 3.66 × 10⁻⁵C
= 3.66 × 10⁻⁵ / 8.854 × 10⁻¹²
= 4.1 × 10⁻⁶ N.M²/C
