Answer:
Explanation:
heat lost by water will be used to increase the temperature of ice
heat gained by ice
= mass x specific heat x rise in temperature
1 x 2090 x t
heat lost by water in cooling to 0° C
= mcΔt where m is mass of water , s is specific heat of water and Δt is fall in temperature .
= 1 x 2 x 4186
8372
heat lost = heat gained
1 x 2090 x t = 8372
t = 4°C
There will be a rise of 4 degree in the temperature of ice.
Answer: Gamma rays
Explanation: The given waves belong to the electromagnetic spectrum which consists of different electromagnetic radiations arranged in terms of increasing wavelengths or decreasing frequencies.
Thus
E= energy
= frequency
c = speed of light
= wavelength
Thus frequency and wavelength are inversely related. The waves having high energies ave high frequencies and have shorter wavelengths.
Thus gamma rays having highest energy have highest frequency and shortest wavelength.
Given Information:
Initial speed = u = 3.21 yards/s
Acceleration = α = 1.71 yards/s²
Final speed = v = 7.54 yards/s
Required Information:
Distance = s = ?
Answer:
Distance = s = 13.61
Explanation:
We are given the speeds and acceleration of the runner and we want to find out how much distance he covered before being tackled.
We know from the equations of motion,
v² = u² + 2αs
Where u is the initial speed of the runner, v is the final speed of the runner, α is the acceleration of the runner and s is the distance traveled by the runner.
Re-arranging the above equation for distance yields,
2αs = v² - u²
s = (v² - u²)/2α
s = (7.54² - 3.21²)/2×1.71
s = 46.55/3.42
s = 13.61 yards
Therefore, the runner traveled a distance of 13.61 yards before being tackled.
Answer: current I = 1.875A
Explanation:
If the resistors are connected in series,
Then the equivalent resistance will be
R = 6 + 18 + 15 + 9
R = 48 ohms
Using ohms law
V = IR
Make current I the subject of formula
I = V/R
I = 90/48
I = 1.875A
And if the resistors are connected in parallel, the equivalent resistance will be
1/R = 1/6 + 1/18 + 1/15 + 1/9
1/R = 0.166 + 0.055 + 0.066 + 0.111
R = 1/0.3999
R = 2.5 ohms
Using ohms law
V = IR
I = 90/2.5
Current I = 35.99A
Answer:
D) True. the protostar rotates more quickly.
Explanation:
If the system is isolated, the angular momentum must be retained.
Initial
L₀ = I w₀
Final
=
L₀ =
I w₀ =
= I / w₀
In general, the radius of the cloud decreases significantly to form the star, the moment of inertia must decrease, so the angular velocity must increase
Let's examine the answers
A) False. The opposite happens
B) False. Speed changes
C) False. For this there must be an external force, which does not exist
D) True. You agree with the above