The acceleration of the rock is the gravitational acceleration due to earth which is around 9.8 m/s^2. As the rock travels upwards it is working against the constant force of gravity and when it reaches the top it is the force of gravity that will cause a cause in the direction of the rocks velocity and cause it to accelerate towards earth. Using the equation a = F/m, the acceleration due to gravity exerts a force per unit mass on an object causing the object to accelerate, anything above earth surface will therefore have an external gravitational force action on it (in terms of projectile motion). So at the top of the rocks trajectory, the acceleration of the rock will be g (9.8) as a constant force is gravity is exerted on the rock throughout its path.
Answer:
Explanation: RADIUS OF EARTH = 6400X1000m =
ACC DUE GRAVITY ABOVE SURFACE OF EARTH = g' =2.45 m/s^2
ACC DUE GRAVITY ON SURFACE OF EARTH =g= 9.8 m/s^2
A/C TO FORmULA
g'/g=1-2h/Re
g'/g +2h/Re = 1
2h/Re =1- g'/g
2h= (1- g'/g)Re
2h=(1-2.45 /9.8)
6400X1000
2h = (0.75)6400X1000
2h = 4800000
h= 2400000
m
Answer:
Explanation:
a )
In space due to weightlessness both astronaut and her oxygen tank will float .
when she throws the tank away from spacecraft , she will have a velocity in opposite direction ie towards the spacecraft . This happens due to conservation of momentum . She creates a momentum away so that she can get a momentum towards the spaceship.
So
m₁ v₁ = m₂v₂
12 x 8 = ( 87 - 12 ) x v₂
v₂ = 1.28 m /s
Time allowed = 2 x 60
= 120 s
So maximum distance upto which she can remain away from spacecraft
= 120 x 1.28
= 153 m .
b )
The Newton's law which explains the theory behind it is "third law of motion" . This law gives law of conservation of momentum .
20 ohms in parallel with 16 ohm= 8.89
20x16/20+16. Product over sum
