I really need help on these Physics questions. Will someone please help me answer them?

Question

What would be the sum of a vectors 10 m East and 10 meters East?

a. 0 m west

b. none of these

c. 20 m East

d. 20 m West

What would happen to the distance travelled by the baseball horizontally, if the height is increase of the cliff from which it was thrown? 

a. decrease

b. can not be determined

d. increase

c. it would remain the same. 

An airplane is flying at a velocity of 145 km/h toward the south as observed by a person on the ground. The pilot measured an air velocity of 172 km/h south. What is the velocity of the wind that affects the plane?

a. 27 km/h north

b. 53 km/h north

c. 53 km/h south

d. 27 km/h south

As a cannonballs falls after it is launched horizontally in the absence of air resistance, at what rate does the cannonball accelerate horizontally? 

a. 0 m/s² because there is no air resistance

b. 9.81 m/s² due to gravity and because there is no air resistance

c. 20 m/s² because there is no air resistance

What would happen to the distance the ball travels horizontally, if the initial velocity that it was thrown is decreased? 

a. can not be determined

b. decrease

c. it would remain the same. 

d. increase

Answer 1

What would be the sum of two vectors 10 m East and 10 meters East? m is the abbreviation for meters, so the answer is c,

a. 0 m west

b. none of these

c. 20 m East

d. 20 m West

What would happen to the distance travelled by the baseball horizontally, if the height is increased of the cliff from which it was thrown? The baseball has a non-zero horizontal velocity, so the longer it is in the air, the farther it will travel horizontally. The answer then is d. The baseball will travel farther, so the distance travelled increases.

a. decrease

b. can not be determined

d. increase

c. it would remain the same. 

An airplane is flying at a velocity of 145 km/h toward the south as observed by a person on the ground. The pilot measured an air velocity of 172 km/h south. What is the velocity of the wind that affects the plane? The size of the effect the wind has on the plane cannot be determined. However, whatever the effect, the plane is traveling 145 km/hour and the wind is blowing faster at 172 km/hour, with both velocities measured in the south direction. At the time the plane was observed, the wind is having a 172-145 = 27 km/hour affect on the plane in the south direction. The answer is d.

a. 27 km/h north

b. 53 km/h north

c. 53 km/h south

d. 27 km/h south

As a cannonball falls after it is launched horizontally in the absence of air resistance, at what rate does the cannonball accelerate horizontally? After a cannonball is launched it accelerates vertically due to gravity, and may decerate horizontally due to air resistance. If we assume no air resistance than the horizontal acceleration = 0. The units of measurement for acceleration is distance/time². So, the answer is a.

a. 0 m/s² because there is no air resistance

b. 9.81 m/s² due to gravity and because there is no air resistance

c. 20 m/s² because there is no air resistance

What would happen to the distance the ball travels horizontally, if the initial velocity that it was thrown is decreased? 

If the initial horizontal velocity is decreased, that does not increase or decrease the amount of time the ball is in the air. However, the distance traveled = time x velocity. So if the time is the same and the horizontal velocity is decreased, the distance traveled decreases. So, the answer is b.

a. can not be determined

b. decrease

c. it would remain the same. 

d. increase