Answer:
The value is 
Explanation:
From the question we are told that
The mass of the bullet is 
The mass of the wood is 
The height attained by the combined mass is 
Generally according to the law of energy conservation
Here 
is the kinetic energy of the bullet before collision.
and 
is the potential energy of the combined mass of bullet and wood at the height h which is mathematically represented as
![PE_m = [m_b + m_w] * g * h](https://tex.z-dn.net/?f=PE_m%20%20%3D%20%20%5Bm_b%20%20%2B%20m_w%5D%20%2A%20%20g%20%2A%20%20h)
So
![KE_b =PE_c = [0.005 + 0.90] * 9.8 *0.08](https://tex.z-dn.net/?f=KE_b%20%3DPE_c%20%20%20%3D%20%5B0.005%20%20%2B%200.90%5D%20%2A%209.8%20%2A0.08)
=>
Answer: The control group is the part where you see what happens when you change a variable you want to study/examine. Basically, you need the control group because you need something to see what happens when you change something.
Hope this Helps! :))))
As you run toward a source of sound, you perceive the frequency of that sound to decrease.
<u>Explanation:</u>
Doppler's effect is a principle used to describe the frequency and the intensity of sound and wavelengths of a source and observer with the two possibilities.
(i) Stationary sound source and moving observer.
(ii) Moving sound source and a stationary observer. It is a relative motion.
Consider when the observer is moving towards a source, the frequency of the sound will be higher and when moving away from the source, the frequency will decrease.
Answer:
180 kJ
Explanation:
Given that:
Mass (m) = 5 kg
Initial temperature (T1) = 28°C
Final temperature (T2) = 68°C
The change in temperature (ΔT) = T2 - T1 = 68°C - 28°C = 40°C
Specific heat capacity of aluminium (c) = 900 J/kg°C
The quantity of heat energy required (q) is given by:
q = mcΔT
q = 5 kg × 900 J/kg°C × 40°C
q = 180000 Joules
q = 180 kJ
Therefore 180 kJ is required to raise the temperature of aluminium from 28°C to 68°C.
Answer:
A
Explanation:
To measure wavelength, you would find the distance from crest (top of the wave) to crest.
Hope this helps! :)
