Use the data table and information below to answer the following questions. A scientist used a laboratory model to test the effect of radiation, or the sun, in heating land and water on Earth. To do this experiment, 200 mL of water and dry sand were placed in to 2 separate 250-mL beakers. Each beaker was then placed under the same lamp. Temperature readings were taken of each substance every 2 minutes for 8 minutes.

Use the data table to answer the following questions.

Substance Heated
Starting Temp (°C)
2 min
4 min
6 min
8 min
Water
18
18.5
19.5
21
22
Dry Sand
18
20
22
24
26

Is this a controlled experiment? Explain.

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j

so she was walking and she stepped on warm jeffy , uh uh uhh dadye i just pooped my pants