Julie drives 100 mi to Grandmother's house. On the way to Grandmother's, Julie drives half the distance at 30.0 mph and half the
1 answer:
Answer:
Explanation:
Given
Distance to grandmother's house=100 mi
it is given that during return trip Julie spend equal time driving with speed 30 mph and 70 mph
Let Julie travel x mi with 30 mph and 100-x with 70 mph
x=30 mi
Therefore
Julie's Average speed on the way to Grandmother's house
=42 mph
On return trip
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Answer:
Explanation:
using the law of the conservation of the linear momentum:
where is the inicial momemtum and
is the final momentum
the linear momentum is calculated by the next equation
P = MV
where M is the mass and V is the velocity.
so:
where m is the mass of the proton and is the velocity of the proton after the collision,
is the mass of the nucleus and
is the velocity of the nucleus after the collision.
therefore, we can formulate the following equation:
m(270 m/s) = m + 14m
then, m is cancelated and we have:
270 = +
This is a elastic collision, so the kinetic energy K is conservated. Then:
and
Kf =
then,
=
here we can cancel the m and get:
=
now, we have two equations and two incognites:
270 = +
(eq. 1)
=
in the second equation, we have:
36450 = (eq. 2)
from this last equation we solve for as:
and replace in the other equation as:
270 = 14
so,
Vp is negative because the proton go in the -i hat direction.
Finally, replacing this value on eq. 1 we get: