Heres one: If you were driving at night, and a car was coming toward you at high speeds, You could tell they were coming because of the increase of sounds and light. Hope this helps!
Answer:
Average speed of the car = 16.53 m.s
Explanation:
For first 5 seconds:
As the car starts from rest, so the initial speed of the car, u=0
Acceleration, a= 4 m/s^2
So, the final speed (speed at time, t=5 second)
v=u+at
v=0 + 4 x 5 = 20 m/s
Distance covered,
s=50 m
As the car maintained the constant speed of 20 m/s for the next 10 seconds.
Distance traveled in 10 seconds, d=20 x 10 =200 m
For the last 4 seconds:
The car slows down at the rate of 2.0 m / s ^ 2 from the speed of 20 m/s.
As the car slows down, so the acceleration will be negative, i.e a=-2 m/s^2
s=80-16=64 m.
Considering all three cases, the total distance covered=
=50+200+64=314 m
Total time= 5+10+4=19 s
So, the averate peed= Totat distance covered / total time taken
=314/19=16.53 m/s
Answer:
When object falls freely we can say
its initial speed will be ZERO
and its acceleration due to gravity must be
a = g = 9.8 m/s^2a=g=9.8m/s2
Now we need to find the distance of free fall in 3 s of time
So here we will use kinematics
y = v* t + \frac{1}{2} at^2y=v∗t+21at2
now we will plug in all values in it
y = 0 + \frac{1}{2}* 9.8 * 3^2y=0+21∗9.8∗32
y = 44.1 my=44.1m
So it will fall by total distance of 44.1 m
Answer: Bohr's model (1913)
Niels Bohr improved Rutherford's model. Using mathematical ideas, he showed that electrons occupy shells or energy levels around the nucleus. The Dalton model has changed over time because of the discovery of subatomic particles.
Bohr's model (1913)
Niels Bohr improved Rutherford's model. Using mathematical ideas, he showed that electrons occupy shells or energy levels around the nucleus. The Dalton model has changed over time because of the discovery of subatomic particles
Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of differing size and mass.
John Dalton
The idea that everything is made of atoms was pioneered by John Dalton (1766-1844) in a book he published in 1808. He is sometimes called the "father" of atomic theory, but judging from this photo on the right "grandfather" might be a better term.
Explanation: