Answer:
(a) 2.5 m/s
(b) 37.5 KJ
Explanation:
(a)
From the law of conservation of momentum, Initial momentum=Final momentum
and making 
the subject then
and since 
is initial velocity of car, value given as 4 m/s, 
is the initial velocity of the three cars stuck together, value given as 2 m/s and 
is the final velocity which is unknown. By substitution
(b)
Initial kinetic energy is given by
Final kinetic energy is given by
The energy lost is given by subtracting the final kinetic energy from the initial kinetic energy hence
Energy lost=350-312.5=37.5 KJ
Answer:
Weight of the dog on surface of earth is 140.14 Newton.
Given:
mass of the dog = 14.3 kg
To find:
Weight of the dog = ?
Formula used:
Weight of the dog is given by,
W = mg
Where, W = weight of the dog
m = mass of the dog
g = acceleration due to gravity
Solution:
Weight of the dog is given by,
W = mg
Where, W = weight of the dog
m = mass of the dog = 14.3 kg
g = acceleration due to gravity
W = 14.3 × 9.8
W = 140.14 Newton
Weight of the dog on surface of earth is 140.14 Newton.
Answer:
ΔU = 2 mg h
Explanation:
In a spring mass system the potential energy is U = m g h
where h is measured from the equilibrium point of the spring
the potential energy at the highest point is
U₁ = m g h
the potential energy at the lowest point is
U₂ = m g (-h)
instead in this energy it is
ΔU = 2 mg h
In this two points the kinetic energy is zero, but there is elastic potential energy that has the same value in the two points, so its change is zero
interesting question.
how much fuel to hover over one place ?
The Foucault pendulum is a v v v long pendulum which can show the eart's rotation over time if the pend bob motion is tracked and recorded
