Answer:
Explanation:
2. A compression wave, like sound, is a kind of <u>mechanical</u> wave.
3. When a wave reflects off a surface, the angle of <u>incidence</u> always equals the angle of <u>reflection</u>.
4. The wailing change of the pitch that you hear as a locomotive approaches and then recedes from you is called <u>Doppler Shift</u>.
Pretty sure it's the last one:
"reduce the size of the input force needed to perform a task"
Answer:
the mass of the raft is 68.4 kg
Explanation:
Since Mass is defined as Volume times Density, start by calculating the volume of the raft:
Volume = length x width x high = 1.5 m x 1.0 m x 0.12 m = 0.18 m^3
and now multiply it times the given density in order to find its mass:
Mass = Volume x Density = 0.18 m^3 x 380 kg/m^3 = 68.4 kg.
Notice that the m^3 units cancel out (they are in numerator and in denominator) leaving just the kg (a unit of mass) in the answer.
Therefore, the mass of the raft is 68.4 kg
Answer:
Explanation:
The minimum distance for takeoff is:
