Answer:
The helicopter was 1103.63 meters high when the package was dropped.
Explanation:
We consider positive speed as a downward movement
y: height (m)
t: time (s)
v₀: initial speed (m/s)
Δy = v₀t + 
gt²
Δy= 15
×15 s + ×9.81
×(15 s)²
Δy= 1103.63 m
Answer:
(a) 
(b) 15 hours
Explanation:
half life, T = 12 hours
No = 19 g
(a) Let N be the amount remaining after time t.
Let λ be the decay constant.
The equation of radioactivity used here is given by
(b) N = 8 gram
Substitute the values in above equation
λ = 0.0577 per hour
So, 
Take natural log on both the sides
- 0.0577 t = - 0.865
t = 15 hours
One reason that it would be appropriate to talk on your cell phone, could be reporting an accident. For instance, a car crash, a sign in the road anything regarding safety of drivers.
Answer:
The acceleration is 0.
Explanation:
The formula for acceleration is:
a = (v-u)/t
If v and u are equal, thus it would be 0 when subtracted, and anything divided by 0 is 0.
Answer: An acid is a substance that donates a proton and produces a conjugate base.
Explanation:
According to Bronsted-Lowry theory, an acid is a substance that donates a proton and produces a conjugate base while a base is a molecule or ion which accepts the proton.
An example of Bronsted-Lowry acid and base is Ethanoic acid, CH3COOH and hydroxide ion, OH- respectively as shown in the reaction below
CH3COOH(aq) + OH-(aq) <---> CH3COO-(aq) + H2O(l)
Thus, ethanoic acid acts as an acid by donating a proton to the hydroxide ion which accepts it, thus producing ethanoate ion, CH3COO- as a conjugate base.
