A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun straight down towards the water.
If air resistance is negligible, the acceleration of the bullets just before they strike the water
A. is greater for the dropped bullet.
B. is greater for the fired bullet.
C. is the same for both bullets.
D. depends on how high they started.
I really should let the physics gurus handle this, but I see they haven't yet. I also see you've posted a lot of questions with no attempt at answers. You aren't expecting us to do your homework are you?
If air resistance is negligible then the formula for a falling object is
s(t)=(-1/2)gt^2+v_0t+s_0
where v_0 is the initial velocity and s_0 is the initial height.
From this we get the velocity of the object at time t
v(t)=-g*t+v_0
For the dropped bullet v_0 is 0
For the fired bullet v_0 is negative.
The question however is concerned with the acceleration. We then get the acceleration as
a(t)=-g
This applies to both objects.
Here's what we can say about the answers:
A. The dropped bullet as 0 initial velocity, but is being upon by gravity.
B. The fired bullet has greater initial velocity, but is being acted upon by gravity.
C. What do you think?
D. Does the height affect the acceleration?
C
The acceleration of the bullets just before they strike the water is the same for both bullets.
To determine the correct answer, let's consider the acceleration of the bullets just before they strike the water.
The acceleration of an object in free fall near the surface of the Earth is due to gravity and is constant. The acceleration due to gravity is approximately 9.8 m/s^2, downward.
In this scenario, both bullets are falling towards the water, so they are both experiencing the same acceleration due to gravity.
Therefore, the correct answer is C. The acceleration is the same for both bullets.
The height from which the bullets are dropped or fired does not affect the acceleration, as long as air resistance is negligible. The acceleration due to gravity remains constant regardless of the initial height.
I hope this explanation helps! Let me know if you have any further questions.
C. The acceleration is the same for both bullets.
Regardless of the initial velocity or height from which the bullets are dropped or fired, the only force acting on them is gravity. Since air resistance is negligible, the only acceleration experienced by both bullets is due to gravity, which is a constant value for objects near the surface of the Earth. Therefore, the acceleration of both bullets just before they strike the water is the same.