Answer: a
Explanation: because the answer is 1.4444444 and that's the closest
<span>Px = 0
Py = 2mV
second, Px = mVcosφ
Py = –mVsinφ
add the components
Rx = mVcosφ
Ry = 2mV – mVsinφ
Magnitude of R = âš(Rx² + Ry²) = âš((mVcosφ)² + (2mV – mVsinφ)²)
and speed is R/3m = (1/3m)âš((mVcosφ)² + (2mV – mVsinφ)²)
simplifying
Vf = (1/3m)âš((mVcosφ)² + (2mV – mVsinφ)²)
Vf = (1/3)âš((Vcosφ)² + (2V – Vsinφ)²)
Vf = (V/3)âš((cosφ)² + (2 – sinφ)²)
Vf = (V/3)âš((cos²φ) + (4 – 2sinφ + sin²φ))
Vf = (V/3)âš(cos²φ) + (4 – 2sinφ + sin²φ))
using the identity sin²(Ď)+cos²(Ď) = 1
Vf = (V/3)âš1 + 4 – 2sinφ)
Vf = (V/3)âš(5 – 2sinφ)</span>
Answer:
Explanation:
Given that,
Lightning flashes one mile (1609 m) away from you.
We need to find the time it take the light to travel that distance. Let the time be t. We know that,
speed = distance/time
So, the required time is 
Answer:
3.1m
Explanation:
Since we only care about the y direction we only need to find vy. Once u draw your vector you will realize that vy= 4.5sin60=3.897m/s.
use vf²=v²+2a(y)
At the maximum height the velocity is 0 and since the object is in freefall, a=-g
Plug in all values
0=15.1875-2*9.8(y)
solve for y
-15.1875*2/-9.8=y
y=3.1m
Increase in temperature of water = 0.53 °C
Explanation:
Change in mechanical energy = Potential energy
Potential energy = mgh
Mass, m = Mass of 1 L water = 1 kg
Acceleration due to gravity, g = 9.81 m/s²
Height, h = 225 m
Potential energy = 1 x 9.81 x 225 = 2207.25 J
Because of this 2207.25 J water gets heated.
Heat energy, E = mcΔT
Mass, m = Mass of 1 L water = 1 kg
Specific heat of water, c = 4200 J/kg/C
Energy, E = 2207.25 J
Change in temperature, ΔT = ?
Substituting
2207.25 = 1 x 4200 x ΔT
ΔT = 0.53 °C
Increase in temperature of water = 0.53 °C
