Given that : d = 5sin(pi t/4), So, maximum displacement, d = 5*(+1) = 5 Also, maximum displacement, d = 5*(-1) = -5
As per the question the distance of venus from sun is given as 0.723 AU
We have been asked to calculate the time period of the planet venus.
As per kepler's laws of planetary motion the square of time period of planet is directly proportional to the cube of semi major axis. mathematically

⇒
where is k is the proportionality constant
We may solve this problem by comparing with the time period of the earth . We know that time period of earth is 365.5 days
Hence
The distance of sun from earth is taken as 1 AU i.e the mean distance of earth from sun
Hence 
The distance of venus from sun is 0.723 AU i.e
From keplers law we know that-
⇒
Putting the values mentioned above we get-

⇒
⇒
Hence the time period of venus is 224.388352752710 days
Density = (mass) / (volume)
4,000 kg/m³ = (mass) / (0.09 m³)
Multiply each side
by 0.09 m³ : (4,000 kg/m³) x (0.09 m³) = mass
mass = 360 kg .
Force of gravity = (mass) x (acceleration of gravity)
= (360 kg) x (9.8 m/s²)
= (360 x 9.8) kg-m/s²
= 3,528 newtons .
That's the force of gravity on this block, and it doesn't matter
what else is around it. It could be in a box on the shelf or at
the bottom of a swimming pool . . . it's weight is 3,528 newtons
(about 793.7 pounds).
Now, it won't seem that heavy when it's in the water, because
there's another force acting on it in the upward direction, against
gravity. That's the buoyant force due to the displaced water.
The block is displacing 0.09 m³ of water. Water has 1,000 kg of
mass in a m³, so the block displaces 90 kg of water. The weight
of that water is (90) x (9.8) = 882 newtons (about 198.4 pounds),
and that force tries to hold the block up, against gravity.
So while it's in the water, the block seems to weigh
(3,528 - 882) = 2,646 newtons (about 595.2 pounds) .
But again ... it's not correct to call that the "force of gravity acting
on the block in water". The force of gravity doesn't change, but
there's another force, working against gravity, in the water.
trueee...................
Answer:
Explanation:
angle covered in one rotation = 2π radian
θ = ωt + 1/2 αt²
θ is angle rotated in time t with initial angular velocity of ω and angular acceleration α .
Putting the values
2π = 0 + 1/2 x α x 3²
α = 1. 4 radian / s²
linear acceleration = α x r = 1.4 x 1.5 = 2.1 m / s².
Initial acceleration = 2.1 m /s²
final angular velocity = α t = 1.4 x 3 = 4.2 radian / s
linear velocity = 4.2 x 1.5 = 6.3 m /s
centripetal acceleration = v² / R = 6.3² / 1.5 = 26.46 m /s²
radian acceleration = 26.46 m /s
tangential acceleration = 2.1 m /s²
Total final acceleration = √ ( 26.46² + 2.1² )
= √ ( 700.13 + 4.41)
Final acceleration = 26.53 m / s²