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
The stage where atoms are spread out and bouncy is the gas stage.
A. True. You can use displacement to determine the volume of solids and liquids.
Answer:

Explanation:
Density can be found by dividing the mass by the volume.

The mass of the quartz is 30 grams and the volume is 6 cubic centimeters.

Substitute the values into the formula.

Divide.

The density of this piece of quartz is 5 grams per cubic centimeter.
Before we answer this question, let us first understand
what alternate hypothesis is.
The alternative hypothesis is the hypothesis which is
used in the hypothesis testing and this is opposite to the null hypothesis.
This is the test hypothesis which is usually taken to be that the observations
are the result of a real effect in an experiment.
In this case since what we want to set up is the
statistical test to see if the waves are dying down, then this means we are
trying to determine if the wave height are decreasing, so lesser than 16.4
feet. Therefore:
The alternative hypothesis would state (ANSWER)
Ha: μ less than 16.4 feet and
P-value area is on the left of the mean.
While the null hypothesis is the opposite and would state
H0: mu equals 16.4 feet