Answer:
H = 1/2 g t^2 where t is time to fall a height H
H = 1/8 g T^2 where T is total time in air (2 t = T)
R = V T cos θ horizontal range
3/4 g T^2 = V T cos θ 6 H = R given in problem
cos θ = 3 g T / (4 V) (I)
Now t = V sin θ / g time for projectile to fall from max height
T = 2 V sin θ / g
T / V = 2 sin θ / g
cos θ = 3 g / 4 (T / V) from (I)
cos θ = 3 g / 4 * 2 sin V / g = 6 / 4 sin θ
tan θ = 2/3
θ = 33.7 deg
As a check- let V = 100 m/s
Vx = 100 cos 33.7 = 83,2
Vy = 100 sin 33,7 = 55.5
T = 2 * 55.5 / 9.8 = 11.3 sec
H = 1/2 * 9.8 * (11.3 / 2)^2 = 156
R = 83.2 * 11.3 = 932
R / H = 932 / 156 = 5.97 6 within rounding
Answer:
V_f = 287.04 mL
Explanation:
We are given the initial/original volume of the glycerine as 285 mL.
Now, after it is finally cooled back to 20.0 °C , its volume is given by the formula;
V_f = V_i (1 + βΔT)
Where;
V_f is the final volume
V_i is the original volume = 285 mL
β is the coefficient of expansion of glycerine and from online tables, it has a value of 5.97 × 10^(-4) °C^(−1)
Δt is change in temperature = final temperature - initial temperature = 32 - 20 = 12 °C
Thus, plugging in relevant values;
V_f = 285(1 + (5.97 × 10^(-4) × 12))
V_f = 287.04 mL
Answer:
Explanation:
Speed can be found by dividing the distance by the time.
The distance is 18 meters and the time is 3 seconds.
Substitute the values into the formula.
Divide.
The speed of the puck is <u>6 meters per second.</u>
For the first one, the correct answer would be "<span>Substance changes its form but not its molecular composition.". During a physical change (let's say cutting paper), the substance has its shape changed, but it is still itself (paper).
</span><span>The second one is a bit trickier: </span>
Kinetic energy of a molecule is directly influenced by temperature. If there is a higher temperature it will have a higher kinetic energy which means the molecule moves at a higher velocity. This will increase the chance of particles bouncing off of each other during the chemical reaction. That explains why the rate of reaction will be higher at a higher temperature, rather than higher at a cool temperature. The correct answer would be lower at 39F.
