How far will this bullet drop in 3 seconds

[MIA6]

1. A bullet is fired horizontally from the roof of a building 100. meteres tall with a speed of 850 meters per second. Neglecting air resistance, how far will the bullet drop in 3.00 seconds?
1) 29.4 m 2) 44.1 m 3) 100. m 4) 2,550
Since the horizontal speed should be constant throughout, so I think 850 is the horizontal initial speed, so I did: 850*3=2550 m, but it's the wrong answer.

2. A ball is being kicked by a foot and rising at an angle of 30 from the horizontal. The ball has an initial velocity of 5.0 meters per second. As the ball rises, the vertical component of its velocity 1) decreases 2) increases 3) remains the same
I think it increases because the vertical component is 5*sin30=2.5, and once the angle increases, then it's 5*sin 45=3.54. So it obviously increased, but the answer is 1) decreases, so I don't know.

Thanks a lot for help.

 

[fizikx]

hint for number one
it's asking how far the bullet dropped, so find its y displacement, not x...

hint for number two
if the ball's velocity continued to increase it wouldn't come back down...also your velocity should look like V = Vosin@ - 1/2gt^2
hope this helps

 

[Moetasim]

I would approach these questions by applying the principles of physics and using relevant equations to solve for the answers. Let's break down each question and its solution:

1. How far will the bullet drop in 3 seconds?

To answer this question, we need to consider the motion of the bullet in both the horizontal and vertical directions. We can use the equation d = v0t + 1/2at^2, where d is the distance, v0 is the initial velocity, t is the time, and a is the acceleration. Since the bullet is fired horizontally, the initial vertical velocity is 0 and the acceleration due to gravity is -9.8 m/s^2. Plugging in the given values, we get:

d = 0 + 1/2(-9.8)(3)^2
d = 44.1 m

Therefore, the bullet will drop 44.1 meters in 3 seconds.

2. As the ball rises, the vertical component of its velocity decreases.

To solve this question, we can use the equation v = v0 + at, where v is the final velocity, v0 is the initial velocity, a is the acceleration, and t is the time. Since the ball is rising, the acceleration due to gravity is acting against its motion, so it will decrease the vertical component of its velocity. We can calculate the final velocity at any given time by using the equation v = v0 + at. In this case, we are interested in the final vertical velocity when the ball reaches its maximum height, so t = 0. The equation becomes:

v = 5*sin30 + (-9.8)(0)
v = 2.5 m/s

Then, we can use the same equation at the peak of the ball's trajectory, when it starts to fall back down. At this point, the time is t = 2.5/9.8 = 0.255 seconds. The equation becomes:

v = 2.5 + (-9.8)(0.255)
v = 0 m/s

As we can see, the vertical component of the velocity has decreased from 2.5 m/s to 0 m/s. Therefore, the correct answer is 1) decreases.

In conclusion, as a scientist, I would use the principles of physics and relevant equations to solve these types of questions. It is important to carefully consider all the