Answer:
10 °C
Explanation:
Applying
q = cm(t₂-t₁)............... Equation 2
Where q = heat energy, c = specific heat of ethanol, m = mass of ethanol, t₁ = initial temperature, t₂ = Final temperature.
Given: c = 2.44 J/g.°C, m = 300 g, q = 14640 J, t₂ = 30°C
Substitute into equation 2 and solve for t₁
14640 = 2.44×300(30-t₁)
14640 = 732(30-t₁)
732(30-t₁) = 14640
(30-t₁) = 14640/732
(30-t₁) = 20
t₁ = 30-20
t₁ = 10 °C
Answer:
in 90 seconds It'll travel 450m At constant speed of 5m/s
Answer:
Explanation:
The energy of a photon is: 
when h is the Planck constant.
Then, we calculate the energy of a photon with a wavelength equal to 550 nm.
To find the number of photons we can use this equation:
Have a nice day!
Answer:
F = 294.3 [N]
Explanation:
To solve this problem we must use Newton's second law which tells us that force is equal to the product of mass by acceleration. It is this particular case the acceleration is due to the gravitational acceleration since the body is in free fall.
Therefore we have:
F = m*g
where:
F = force [N]
m = mass = 30 [kg]
g = gravity acceleration = 9.81 [m/s^2]
F = 30*9.81
F = 294.3 [N]
