Gravity increased the downward speed (or decreases the upward speed) by 9.8 m/s every second.
21.2/9.8 = 2.2 seconds
Answer:
t = 2.58*10^-6 s
Explanation:
For a nonconducting sphere you have that the value of the electric field, depends of the region:

k: Coulomb's constant = 8.98*10^9 Nm^2/C^2
R: radius of the sphere = 10.0/2 = 5.0cm=0.005m
In this case you can assume that the proton is in the region for r > R. Furthermore you use the secon Newton law in order to find the acceleration of the proton produced by the force:

Due to the proton is just outside the surface you can use r=R and calculate the acceleration. Also, you take into account the charge density of the sphere in order to compute the total charge:

with this values of a you can use the following formula:

hence, the time that the proton takes to reach a speed of 2550km is 2.58*10^-6 s
Answer: A light bulb can be all of the following except option C (a consumer product if it is used to light the office of the board of directors.)
Explanation:
Products are classified as being BUSINESS or CONSUMER products according to the buyer's intended use of the product.
-Consumer products: these are sold goods that are used for personal, family, or household use. The intention of the buyer is for the products to satisfy his personal needs and desires. Example of some of the consumer products include: toothpaste, eatables and clothes.
Business products: products that are not for personal use but for the manufacturing of other goods are called business products.
Therefore a bulb is not serving as a personal use when used to light the office of the board of directors rather it's serving as a business product .
Im sure the answer is letter B