Answer:
17.2 seconds
Explanation:
Given:
v₀ = 0 m/s
a₁ = 10.0 m/s²
t₁ = 3.0 s
a₂ = 16 m/s²
t₂ = 5.0 s
a₃ = -12 m/s²
v₃ = 0 m/s
Find: t
First, find v₁:
v₁ = a₁t₁ + v₀
v₁ = (10.0 m/s²) (3.0 s) + (0 m/s)
v₁ = 30 m/s
Next, find v₂:
v₂ = a₂t₂ + v₁
v₂ = (16 m/s²) (5.0 s) + (30 m/s)
v₂ = 110 m/s
Finally, find t₃:
v₃ = a₃t₃ + v₂
(0 m/s) = (-12 m/s²) t₃ + (110 m/s)
t₃ = 9.2 s
The total time is:
t = t₁ + t₂ + t₃
t = 3.0 s + 5.0 s + 9.2 s
t = 17.2 s
Round as needed.
According to Newton`s law. Force exerted by car,

After adding an additional 400 kg of mass, the force will be same therefore the acceleration

Thus, the acceleration after adding the masses is 1.47 \ m/s^2.
The penny will reach terminal velocity at 50 ft. Then it will travel 25 mph till it reaches ground.
Answer:
Potential Energy = 294J, Kinetic Engergy = 48.02J
Explanation:
We have these formulas:
Potential Energy = mass * gravitational force * height (m) = 1 * 9.8 * 30 = 294(J)
Kinetic Energy = 1/2 * mass * velocity^2 = 1/2 * 1 * 9.8^2 = 48.02 (J)
As the rock falling at an acceleration of 9.8m/s^2 which means for each second, the rock increases 9.8m/s. I think we are missing time to find the instantaneous velocity, the formula is (initial displacement - final displacement)/ (initial time - final time) which will directly give the final answer for you.
The answer is B. because NaCl are just two elements with one atom from each element