If continuous spectrum light from a star passes through a cool, low-density gas on its way to your telescope and spectroscope, _
1 answer:
You might be interested in
Answer:
v = 8.1 m/s
θ = -36.4º (36.4º South of East).
Explanation:
- Assuming no external forces acting during the collision (due to the infinitesimal collision time) total momentum must be conserved.
- Since momentum is a vector, if we project it along two axes perpendicular each other, like the N-S axis (y-axis, positive aiming to the north) and W-E axis (x-axis, positive aiming to the east), momentum must be conserved for these components also.
- Since the collision is inelastic, we can write these two equations for the momentum conservation, for the x- and the y-axes:
- We can go with the x-axis first:
⇒
- Replacing by the givens, we can find vfx as follows:
- We can repeat the process for the y-axis:
⇒
- Replacing by the givens, we can find vfy as follows:
- The magnitude of the velocity vector of the wreckage immediately after the impact, can be found applying the Pythagorean Theorem to vfx and vfy, as follows:
- In order to get the compass heading, we can apply the definition of tangent, as follows:
⇒ tg θ = vfy/vfx = (-4.8m/s) / (6.5m/s) = -0.738 (9)
⇒ θ = tg⁻¹ (-0.738) = -36.4º
- Since it's negative, it's counted clockwise from the positive x-axis, so this means that it's 36.4º South of East.
Answer:
Approximately .
Explanation:
Momentum would be conserved since there's no friction on this friend, and all other forces on her are balanced. Therefore:
.
Momentum the product of mass
and velocity
. That is:
.
The initial momentum of this friend is since she was initially not moving (an initial velocity of
.)
The initial momentum of the pumpkin would be:
.
Therefore:
.
Rearrange the equation to find an expression for velocity
given momentum and mass:
.
Note that the "final momentum of friend and pumpkin" in the previous equation refers to the resultant velocity of the friend with the pumpkin in her hand. Thus, it would necessary to use the combined mass of the friend and the pumpkin when calculating the resultant velocity:
.