Incomplete question as the unit of volume is not written correctly.So the complete question is here:
A straightforward method of finding the density of an object is to measure its mass and then measure its volume by submerging it in a graduated cylinder. What is the density of a 240-g rock that displaces 89.0 cm³?
Answer:

Explanation:
Given data
Mass m=240g
Volume V=89.0 cm³
To find
Density d
Solution
If rock displaces 89.0 cm³ of water means volume of rock is also 89cm³
So

-- The vertical component of the ball's velocity is 14 sin(<span>51°) = 10.88 m/s
-- The acceleration of gravity is 9.8 m/s².
-- The ball rises for 10.88/9.8 seconds, then stops rising, and drops for the
same amount of time before it hits the ground.
-- Altogether, the ball is in the air for (2 x 10.88)/(9.8) = 2.22 seconds
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-- The horizontal component of the ball's velocity is 14 cos(</span><span>51°) = 8.81 m/s
-- At this speed, it covers a horizontal distance of (8.81) x (2.22) = <em><u>19.56 meters</u></em>
before it hits the ground.
As usual when we're discussing this stuff, we completely ignore air resistance.
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Answer:
The speed traveled by the car is 40 meter per second.
Explanation:
The formula for the relation between the power and the force is as follows:
P = Fv
Where F is the force and v is the speed.
As given
To travel at constant speed, a car engine provides 24KW of useful power. The driving force on the car is 600N.
F = 600 N
Convert power from KW to W.
1 KW = 1000 W
24 KW = 24 × 1000 W
= 24000 W
Thus
P = 24000 W
Put these values in the formula.
24000 = 600 × v
24000 = 600v

v = 40 meter per second .
Therefore the speed of the car is 40 meter per second .
You need to use Planck's law:
E = h·υ = (h·c)/λ
Without making all the calculations, a fraction is bigger than another when the denominator is smaller. Therefore you need to find the smallest wavelength (λ) which is 450nm.
You could also be helped by colors: in order of decreasing energy, you have blue - green - yellow - red.
In any case, the correct answer is a).
Answer: 1
Explanation:
Given
Tension is the string 
mass of object 
Tension is greater than the weight of the object i.e. elevator is moving upward
we can write
