Impulse = Change in momentum.
The ball was moving with a momentum of 0.45 * 22 = 9.9
The ball comes to rest in the receivers arm; this means the ball's final velocity = 0. So mv2 = 0.45 * 0
The magnitude of the impact is just the change in momentum. 9.9 - (0.45 * 0) = 9.9
To solve this problem we must basically resort to the kinematic equations of movement. For which speed is defined as the distance traveled in a given time. Mathematically this can be expressed as
Where
d = Distance
t = time
For which clearing the time we will have the expression
Since we have two 'fluids' in which the sound travels at different speeds we will have that for the rock the time elapsed to feel the explosion will be:
In the case of the atmosphere -composite of air- the average speed of sound is 343m / s, therefore it will take
The total difference between the two times would be
Therefore 3.357s will pass between when they feel the explosion and when they hear it
Answer:
D, rubber
Explanation:
Metals have free electrons, and are very bad as insultators. Metals conduct electricity very well. On the other hand, rubber has no free electrons and does not conduct electricity very well
Answer:
4.08 kg
Explanation:
We can apply the Newton's second law of motion to find the mass of this object:
,
where 
is mass, and 
is acceleration, which is substituted by 
here. Now, plugging given numbers in the equation, we have
.
Solving for mass, we have
Answer:
11.3 m/s
Explanation:
First, find the time it takes for the first stone to fall 3.2 m.
Given:
Δy = 3.2 m
v₀ = 0 m/s
a = 9.8 m/s²
Find: t
Δy = v₀ t + ½ at²
(3.2 m) = (0 m/s) t + ½ (9.8 m/s²) t²
t = 0.81 s
Next, find the time for the first stone to land.
Given:
Δy = 15 m
v₀ = 0 m/s
a = 9.8 m/s²
Find: t
Δy = v₀ t + ½ at²
(15 m) = (0 m/s) t + ½ (9.8 m/s²) t²
t = 1.75 s
The difference in time is 1.75 s − 0.81 s = 0.94 s. Find the initial velocity needed for the second stone to land after that amount of time.
Given:
Δy = 15 m
a = 9.8 m/s²
t = 0.94 s
Find: v₀
Δy = v₀ t + ½ at²
(15 m) = v₀ (0.94 s) + ½ (9.8 m/s²) (0.94 s)²
v₀ = 11.3 m/s
