They are right the answer is A true
Ox:vₓ=v₀
x=v₀t
Oy:y=h-gt²/2
|vy|=gt
tgα=|vy|/vₓ=gt/v₀=>t=v₀tgα/g
y=0=>h=gt²/2=v₀²tg²α/2g=>tgα=√(2gh/v₀²)=√(2*10*20/24²)=√(400/576)=0.83=>α=tg⁻¹0.83=39°
cosα=vₓ/v=v₀/v=>v=v₀/cosα=24/cos39°=24/0,77=31.16 m/s
Ec=mv²/2=2*31.16²/2=971.47 J=>Ec≈0.97 kJ
Answer:
The moon keeps the same face pointing towards the Earth because its rate of spin is tidally locked so that it is synchronized with its rate of revolution (the time needed to complete one orbit). In other words, the moon rotates exactly once every time it circles the Earth.
Answer:
I think it's 2 the photo is hard to tell what they are exactly talking about.
Answer:
The acceleration is 1 cm/s^2.
Explanation:
The acceleration is defined as the rate of change of velocity.
Here, initial velocity, u = 3/1 = 3 cm/s
final velocity, v = 4/1 = 4 cm/s
time, t = 1 s
Let the acceleration is a.
Use first equation of motion
v = u + at
4 = 3 + 1 x a
a = 1 cm/s^2