6 months with no sunrise and the other 6 without a sunset, at some places on Earth, are the result of the orientation of Earth's axis.
Answer: - 7500N
Explanation:
Given the following :
Initial Velocity of car = 108km/hr
Time taken to stop after applying brakes = 4s
Mass of passengers in car = 1000kg
Force exerted by the brakes on the car =?
After 4s, then final Velocity (V) = 0
Initial Velocity (u) of the car = 108km/hr
108km/hr = (108 × 1000)m ÷ (3600)s = 30m/s
Force exerted = mass(m) × acceleration(a)
Acceleration of car = Change in Velocity with time
a = (v - u) / t
a = (0 - 30) / 4
a = - 30/ 4
a = - 7.5m/s^2
Therefore,
Force exerted = mass(m) × acceleration(a)
Force exerted = 1000kg × (-7.5)m/s^2
Force exerted = - 7500N
Answers:
a) 122.5 m
b) 50 m
Explanation:
Here we are dealing with projectile motion, where we can use the following two equations that model the parabolic motion of the stone after being thrown from the window:
(1)
(2)
Where:
is the height of the stone when it hits the ground
is the initial height of the stone
is the initial velocity of the stone
since we are told the stone was thrown horizontally
is the time the stone is in air
is the horizontal distance the stone travelled
Knowing this, we can answer the questions:
a)Initial height of the stone:
In this case we will isolate from (1):
(3)
(4)
(5) This is the initial height
b) Horizontal distance:
In this case we will use equation (2):
(6)
(7) This is the horizontal distance