Answer:
the energy when it reaches the ground is equal to the energy when the spring is compressed.
Explanation:
For this comparison let's use the conservation of energy theorem.
Starting point. Compressed spring
Em₀ = K_e = ½ k x²
Final point. When the box hits the ground
Em_f = K = ½ m v²
since friction is zero, energy is conserved
Em₀ = Em_f
1 / 2k x² = ½ m v²
v = x
Therefore, the energy when it reaches the ground is equal to the energy when the spring is compressed.
Answer:
Explanation:
1.)
2.) COP
3.) Rate of heat absorption
COP
Therefore, cooling in minutes=
COP cannot cycle=
Rate of heat absorption
cooling time in minutes with cannot cycle
True. For example the Big Bang theory; no one knows what really happened, but based on evidences that were found, it was found as a good way to explain the world's origin.
Answer:
Explanation:
Given that:
If we let the piece of the close lose contact at ∠θ;
Then ; from force balance;
we have:
where;
Again:
Answer:
6.35 m/s
Explanation:
The motion of the salmon is equivalent to that of a projectile, which consists of two independent motions:
- A horizontal motion with constant speed
- A vertical motion with constant acceleration (, acceleration of gravity)
The horizontal velocity of the salmon is given by:
where
u = ? is the initial speed
is the angle of projection
Then the horizontal distance covered by the salmon after a time t is given by
Or equivalently, the time taken to cover a distance d is
(1)
Along the vertical direction, the equation of motion is
(2)
where
is the initial vertical velocity
If we substitute (1) into (2), we get:
We now that in order to reach the breeding grounds, the salmon must travel a distance of
d = 2.02 m
reaching a height of
h = 0.574 m
Substituting these data into the equation and solving for u, we find the initial speed that the salmon must have: