Answer:
A) 2.89 × 105 N/C, radially inward
Explanation:
The magnitude of the electric field generated by a charged sphere is given by the following formula:
( 1 )
k: Coulomb's constant = 8.98*10^9 Nm^2/C^2
Q: charge of the sphere = -6.50*10^-6 C
r: distance from the center of the sphere to the point in which E is calculated
r = 0.150m + 0.300m = 0.450 m
You replace the values of Q and r in the equation (1):

The electric field points radially inward because the charge is negative.
hence, the answer is:
A) 2.89 × 105 N/C, radially inward
Answer:
See explanation
Explanation:
Since the original count rate is 600 Bq,
i) after 1 half life, the count rate decreases to 1/2 of 600 Bq = 300 Bq
ii) after 2 half lives, the count rate decreases to 1/4 of 600 = 150 Bq
iii) after 3 half lives, the count rate decreases to 1/6 of 600 = 100 Bq
iv) after 4 half lives, the count rate decreases to 1/8 of 600 = 75 Bq
25 meters per second.
To find this, divided 150 by 6 in order to get the correct calculation.
Hope this helps!
They have thick body coverings