Answer:
a = 0.0505 [m/s^2]
Explanation:
In order to solve this formula we must use the following formula of kinematics.
where:
x = distance = 50000 [m]
Vo = initial velocity = 0
a = acceleration [m/s^2]
t = time = 23 [min] = 1380 [s]
Note: the positive sign in the above equation shows that the car accelerates.
50000 = (0*1380) + (0.5*a*1380^2)
a = 0.0525 [m/s^2]
But we can calculate the acceleration using the following formula:
where:
Vf = final velocity = 67 [m/s]
67 = 0 + (a*1380)
a = 0.0485 [m/s^2]
We can see that by means of kinematics and with the given values we can find two values of accelerations, however, we can determine the average acceleration, by means of the mathematical average.
a = (0.0485 + 0.0525) / 2
a = 0.0505 [m/s^2]
Answer:
a = - e E / m
a = - 1,758 10¹¹ E
Explanation:
For this exercise we can use Newton's second law
F = m a
where the force is electric
the forces given by the product of the charge by the electric field
F = q E
in this case tell us that the charge is the charge of the electron
q = -e = - 1.6 10⁻¹⁹ C
we substitute
- e E = m a
a = - e E / m
we calculate
a = - 1.6 10⁻¹⁹ / 9.1 10⁻³¹ E
a = - 1,758 10¹¹ E
The negative sign indicates that the acceleration is in the opposite direction to the electric field
Answer:
let the age of elder sister = x+8
then let the age of younger sister be x
sum of their ages = 64
according to the question,
x+8+x = 64
2x+8 = 64
2x = 64-8
2x = 56
x = 56/ 2
x = 28
so, the age of younger sister is 28 years
and the age of elder sister is x+8= 28+8= 36years