Answer:
(a) t = 0.75 s
(b) d = 26 m
Explanation:
Height, h = 12 m
Angle, A = 30 degree
initial velocity, u = 40 m/s
(a) Let the time is t.
Use second equation of motion
![h = u t + 0.5 at^2\\\\12 = 40 sin 30 t - 0.5 \times10 \times t^2\\\\12 = 20 t - 5 t^2\\\\5 t^2 - 20 t + 12 =0 \\\\t = \frac{20\pm \sqrt{400-240}}{10}\\\\t = \frac{20\pm 12.65}{10}\\\\t = 3.3 s, 0.75 s](https://tex.z-dn.net/?f=h%20%3D%20u%20t%20%2B%200.5%20at%5E2%5C%5C%5C%5C12%20%3D%2040%20sin%2030%20t%20-%200.5%20%5Ctimes10%20%5Ctimes%20t%5E2%5C%5C%5C%5C12%20%3D%2020%20t%20-%205%20t%5E2%5C%5C%5C%5C5%20t%5E2%20-%2020%20t%20%2B%2012%20%3D0%20%5C%5C%5C%5Ct%20%3D%20%5Cfrac%7B20%5Cpm%20%5Csqrt%7B400-240%7D%7D%7B10%7D%5C%5C%5C%5Ct%20%3D%20%5Cfrac%7B20%5Cpm%2012.65%7D%7B10%7D%5C%5C%5C%5Ct%20%3D%203.3%20s%2C%200.75%20s)
(b) d = u cos A t
d = 40 x cos 30 x 0.75 = 26 m
I don't see any answers, but I do know that machines help for example: make chocolate bars. people do not have to cut the bars or another example: salt or season chips. or washing laundry. or electric cutters help so we do not have to do it by hand or with a knife.
Does this Help?
Visible light is the only light visible to the human eye.
Answer:
L = 0.24 m = 24 cm
Explanation:
Given:
- Wavelength of the wave λ = 12 cm
- total number of nodes : mode @ each end = 2 , 3 nodes in between = 5 nodes
Find:
How wide is the oven?
Solution:
- The wavelength of the microwave corresponds to a frequency of:
f = c / λ
f = 3.0*10^8 / 0.12
f = 25 * 10^8 Hz
- We have a total of 5 nodes, hence we get m = 4 anti-nodes in our standing wave.
- The frequency of a standing wave @ m of length L fixed at both ends is given by:
f_m = m*c / 2*L m = 1 , 2, 3 , 4, ....
L = m*c / 2*f_m
- Plug in values:
L = 4*3 / 2*25
L = 0.24 m = 24 cm
Answer:
Mass, m = 6 kg
Explanation:
Given that,
The momentum of the object, p = 18 kg-m/s
Velocity, v = 3 m/s
We need to find the mass of an object.
The momentum of an object is given by :
p = mv
m is mass of the object
![m=\dfrac{p}{v}\\\\m=\dfrac{18\ kg-m/s}{3\ m/s}\\\\m=6\ kg](https://tex.z-dn.net/?f=m%3D%5Cdfrac%7Bp%7D%7Bv%7D%5C%5C%5C%5Cm%3D%5Cdfrac%7B18%5C%20kg-m%2Fs%7D%7B3%5C%20m%2Fs%7D%5C%5C%5C%5Cm%3D6%5C%20kg)
So, the mass of the object is 6 kg.