I think you almost got it.
At the top, the velocity only has horizontal component, so v=12 m/s is v_x, which is v*cos(theta), because v_x is constant, so the same when it was launched or now.
With the value of the initial speed (28 m/s, which is the total speed), you can set
v_x = v * cos( theta ) ---> 12 = 28*cos(theta) --> cos(theta)=12/28=3/7
or theta = 64.62 deg, it is D. Think about it. I hope you see it.
Answer:
The work done by this engine is 800 cal
Explanation:
Given:
100 g of water
120°C final temperature
22°C initial temperature
30°C is the temperature of condensed steam
Cw = specific heat of water = 1 cal/g °C
Cg = specific heat of steam = 0.48 cal/g °C
Lw = latent heat of vaporization = 540 cal/g
Question: How much work can be done using this engine, W = ?
First, you need to calculate the heat that it is necessary to change water to steam:
![Q_{1} =m_{w} C_{w} (100-22)+m_{w}L_{w}+m_{w}C_{g}(120-100)](https://tex.z-dn.net/?f=Q_%7B1%7D%20%3Dm_%7Bw%7D%20C_%7Bw%7D%20%28100-22%29%2Bm_%7Bw%7DL_%7Bw%7D%2Bm_%7Bw%7DC_%7Bg%7D%28120-100%29)
Here, mw is the mass of water
![Q_{1} =(100*1*78)+(100*540)+(100*0.48*20)=62760cal](https://tex.z-dn.net/?f=Q_%7B1%7D%20%3D%28100%2A1%2A78%29%2B%28100%2A540%29%2B%28100%2A0.48%2A20%29%3D62760cal)
Now, you need to calculate the heat released by the steam:
![Q_{2} =m_{w}C_{g}(120-100)+m_{w}L_{w}+m_{w}C_{w}(100-30)=(100*0.48*20)+(100*540)+(100*1*70)=61960cal](https://tex.z-dn.net/?f=Q_%7B2%7D%20%3Dm_%7Bw%7DC_%7Bg%7D%28120-100%29%2Bm_%7Bw%7DL_%7Bw%7D%2Bm_%7Bw%7DC_%7Bw%7D%28100-30%29%3D%28100%2A0.48%2A20%29%2B%28100%2A540%29%2B%28100%2A1%2A70%29%3D61960cal)
The work done by this engine is the difference between both heats:
![W=Q_{1}-Q_{2}=62760-61960=800cal](https://tex.z-dn.net/?f=W%3DQ_%7B1%7D-Q_%7B2%7D%3D62760-61960%3D800cal)
Answer:
The earthquake occurred at a distance of 1122 km
Explanation:
Given;
speed of the P wave, v₁ = 8.5 km/s
speed of the S wave, v₂ = 5.5 km/s
The distance traveled by both waves is the same and it is given as;
Δx = v₁t₁ = v₂t₂
let the time taken by the wave with greater speed = t₁
then, the time taken by the wave with smaller speed, t₂ = t₁ + 1.2 min, since it is slower.
v₁t₁ = v₂t₂
v₁t₁ = v₂(t₁ + 1.2 min)
v₁t₁ = v₂(t₁ + 72 s)
v₁t₁ = v₂t₁ + 72v₂
v₁t₁ - v₂t₁ = 72v₂
t₁(v₁ - v₂) = 72v₂
![t_1 = \frac{72v_2}{v_1-v_2}\\\\t_1 = \frac{72*5.5}{8.5-5.5}\\\\t_1 = 132 \ s](https://tex.z-dn.net/?f=t_1%20%3D%20%5Cfrac%7B72v_2%7D%7Bv_1-v_2%7D%5C%5C%5C%5Ct_1%20%3D%20%20%20%5Cfrac%7B72%2A5.5%7D%7B8.5-5.5%7D%5C%5C%5C%5Ct_1%20%3D%20132%20%5C%20s)
The distance traveled is given by;
Δx = v₁t₁
Δx = (8.5)(132)
Δx = 1122 km
Therefore, the earthquake occurred at a distance of 1122 km
Answer:
coins made with the combination of copper zinc and Nickel
A cloth is made of fabrics
A towel is made from cotton
an umbrella is made up of fiberglass
a sweater is made up of wool
hope it helps
please mark me as the brainliest
What are the answers to choose from