Answer:
Water normally freezes at 0°C (32°F). Salt lowers the freezing temperature. (That is, it can remain a liquid at much lower temperatures.)
When sprinkled on ice, the salt lowers the freezing temperature of the water which effectively melts the ice when the salt dissolves into it. There is a limit to how low it can reduce the temperature, though. If the temperature drops below -9°C (15°F), it's too cold for the salt to dissolve into the ice.
When making ice cream, the salt lowers the temperature of the ice and water sufficiently enough to freeze the cream.
Answer:
Ratio of series current to parallel
= 1 : 8
Explanation:
Total resistance Rt
For series, Rt = 2+2+2+2 = 4ohms
For parallel, 1/Rt = 1/2 + 1/2 + 1/2 + 1/2
1/Rt = 4/2, Rt = 2/4 ohms.
If we use a 1V battery, then,
I = V/Rt
I = 1/4 = 0.25 ampere for series arrangement.
I = 1/0.5 = 2 ohms.
Ratio of current of series to parallel = 0.25 : 2
= 1 : 8
Compute first for the vertical motion, the formula is:
y = gt²/2
0.810 m = (9.81 m/s²)(t)²/2
t = 0.4064 s
whereas the horizontal motion is computed by:
x = (vx)t
4.65 m = (vx)(0.4064 s)
4.65 m/ 0.4064s = (vx)
(vx) = 11.44 m / s
So look for the final vertical speed.
(vy) = gt
(vy) = (9.81 m/s²)(0.4064 s)
(vy) = 3.99 m/s
speed with which it hit the ground:
v = sqrt[(vx)² + (vy)²]
v = sqrt[(11.44 m/s)² + (3.99 m/s)²]
v = 12.12 m / s
Answer:
4.7 x 10³ rad / s
Explanation:
During the time light goes and comes back , one slot is replaced by next slot while rotating before the light source
Time taken by light to travel a distance of 2 x 500 m is
= (2 x 500) / 3 x 10⁸
= 3.333 x 10⁻⁶ s .
In this time period, two consecutive slots come before the source of light one after another by rotation. There are 400 slots so time taken to make one rotation
= 3.333 x 10⁻⁶ x 400
= 13.33 x 10⁻⁴ s
This is the time period so
T = 13.33 X 10⁻⁴
Angular speed
= 2π / T
= 
4.7 x 10³ rad / s
Answer:
αβ = Ma
Explanation:
By Newton's 2nd Law, the equation governing the motion of the rocket while the rocket is burning fuel is
αβ = Ma where α = rocket's fuel burning rate, β = relative to the velocity of the rocket, M = instantaneous mass of the rocket and a = acceleration of rocket.
