Answer:
v = -1.8t+36
20 seconds
360 m
40 seconds
36 m/s
The object speed will increase when it is coming down from its highest height.
Explanation:
Differentiating with respect to time we get
a) Velocity of the object after t seconds is v = -1.8t+36
At the highest point v will be 0
b) The object will reach the highest point after 20 seconds
c) Highest point the object will reach is 360 m
d) Time taken to strike the ground would be 20+20 = 40 seconds
![[tex]v=u+at\\\Rightarrow v=0+0.9\times 2\times 20\\\Rightarrow v=36\ m/s](https://tex.z-dn.net/?f=%5Btex%5Dv%3Du%2Bat%5C%5C%5CRightarrow%20v%3D0%2B0.9%5Ctimes%202%5Ctimes%2020%5C%5C%5CRightarrow%20v%3D36%5C%20m%2Fs)
Acceleration will be taken as positive because the object is going down. Hence, the sign changes. 2 is multiplied because the expression is given in the form of 
e) The velocity with which the object strikes the ground will be 36 m/s
f) The speed will increase when the object has gone up and for 20 seconds and falls down for 20 seconds. The object speed will increase when it is coming down from its highest height.
Something is reproducing.
Answer: 0.85 meters (with and without sigfigs)
Explanation: To find the wavelength, you just have to switch around the equation for wave speed: v (wave speed) = λ (wavelength)*f (frequency) so λ (wavelength) = v (wave speed)/f (frequency). You don't have the wave speed but you can calculate it. Since wave speed is measured in meters/second or m/s, you just have to divide the amount of meters you were given by the amount of seconds. You will get 340 m/s. Next, you have to plug the values into the equation: λ (wavelength) = 340 m/s (wave speed)/400 Hz (frequency). The answer is 0.85 meters (seconds cancel) and has the correct number of significant figures.
Answer:
d = 20.25 m
Explanation:
h = 6m, V = 14 m/s, θ=14°
⇒ Vx=V × Cosθ=13.58 m/s and Vy = V × Sinθ=3.39 m/s
to find time t by h=-Vy t + 1/2 g t² (after putting value and simplifying) (-ve for downward motion)
4.9 t² - 3.39 t - 6 =0
⇒ t=1.5 sec (ignoring -ve root)
Now Vx = d/t
13.5 m/s = d / 1.5 s ⇒ d = 20.25 m
Answer:
Substances can change phase — often because of a temperature change. At low temperatures, most substances are solid; as the temperature increases, they become liquid; at higher temperatures still, they become gaseous.
Explanation:
