Answer:
0° C
Explanation:
Given that
Mass of ice, m = 50g
Mass of water, m(w) = 50g
Temperature of ice, T(i) = 0° C
Temperature of water, T(w) = 80° C
Also, it is known that
Specific heat of water, c = 1 cal/g/°C
Latent heat of ice, L(w) = 89 cal/g
Let us assume T to be the final temperature of mixture.
This makes the energy balance equation:
Heat gained by ice to change itself into water + heat gained by melted ice(water) to raise its temperature at T° C = heat lost by water to reach at T° C
m(i).L(i) + m(i).c(w)[T - 0] = m(w).c(w)[80 - T], on substituting, we have
50 * 80 + 50 * 1(T - 0) = 50 * 1(80 - T)
4000 + 50T = 4000 - 50T
0 = 100 T
T = 0° C
Thus, the final temperature is 0° C
<span>31.3 m/s
Since the water balloon is being launched at a 45 degree angle, the horizontal and vertical speeds will be identical. Also the time the balloon takes to reach its peak altitude will match the time it takes to fall. So let's create a few expressions about what we know.
Distance the water balloon travels at velocity v for time t
d = vt
Total time required for the entire trip is double since the balloon goes up, then goes down
t = 2v/a
Now let's plug in the numbers we have, assuming the acceleration due to gravity is 9.8 m/s^2
t = 2v/9.8
100 = vt
Substitute 2v/9.8 for t in the 2nd formula
100 = v(2v/9.8)
Solve for v.
100 = v(2v/9.8)
100 = 2v^2/9.8
980. = 2v^2
490 = v^2
22.13594 = v
So we now know that both the horizontal velocity and vertical velocity needed is 22.13594 m/s. Let's verify that
2*22.13594 / 9.8 = 4.51754
So it will take 4.51754 second for the balloon to hit the ground after being launched.
4.51754 * 22.13594 = 100
And during that time it will travel 100 meters horizontally.
But we need to know the total velocity. And the Pythagorean theorem comes to the rescue. Just square the 2 velocities, add them together, and take the square root. We already know the square is 490 from the work above, so
sqrt(490+490) = sqrt(980) = 31.30495 m/s</span>
Answer:
Speed of physicist car is 0.036c or 1.08 x 10⁷ m/s .
Explanation:
Doppler Effect is defined as the change in frequency or wavelength of the wave as the source or/and observer moving away or towards each other.
In this case, the Doppler effect equation in terms of wavelength is :
......(1)
Here 
is source wavelength, 
is observed wavelength, v is speed of the observer and c is the speed of light.
Given :
Source wavelength, = 660 nm = 660 x 10⁻⁹ m
Observed wavelength, 
= 555 nm = 555 x 10⁻⁹ m
Substitute these values in the equation (1).
v = 1.08 x 10⁷ m/s
Answer:
V = λ f (wavelength * frequency)
λ = V / f = 343 m/s / 262 / s = 1.3 m
Answer;
Average speed = 47.5 km/hr
Explanation and solution;
Average Speed = Total distance /Total time
Total distance;
-In the first two hours travelling at 40km/hr, total distance traveled is 80km.
(40 × 2) = 80 km
-In next two hours distance covered is 110 km. (55 ×2)
Total distance = 110 + 80 = 190 km
Total time = 2 + 2 = 4 hours
Average Speed = Total distance /Total time
= 190/4
= 47.5 km/hr
