Answer: a graduated cylinder and balance
A rock has an irregular shape. so, it would be difficult to measure using a meter stick. most convenient method to find the volume would be using a graduated cylinder. we can take a fixed volume of water in the cylinder. then drop rock into it. note the new raised volume. Subtract the initial volume from final to find the volume of rock.
Using balance, mass of the rock can be measured.
we can calculate the density using the following formula:
Therefore, we need only two tools, a graduated cylinder and a balance to measure mass, volume and density of a rock.
Answer:
Explanation:
Using Hooke's law
Elastic potential energy = 1/2 K x²
K is elastic constant of the spring
x is the extension of the spring
a) The elastic potential energy when the spring is compressed twice as much Uel = 1/2 k (2x₀) ² = 4 (1/2 kx₀²)= 4 U₀
b) when is compressed half as much Uel = 1/2 k 
= 
( U₀)
c) make x₀ subject of the formula in the equation for elastic potential
x₀ =
x, the amount it will compressed to tore twice as much energy = 
x = √2 x₀
d) x₁, the new length it must be compressed to store half as much energy = 
x₁ = 
x₀
I’m pretty sure it’s the caused by the pressure difference. Things always want to move from high to low pressure so the interior would be higher pressure than the outside. Which causes the suction effect
Answer:
10.6 s
Explanation:
Given that a girl is running the 200 m dash. She starts by acceleration at 8m/s^2 for 7s. Then continues at this speed until the end of the race. How long did it take for her to complete the race?
Solution.
If she accelerated for 7s, the velocity at which she accelerated will be:
Acceleration = velocity/time
8 = V/7
Make V the subject of the formula by cross multiplying.
V = 8 × 7
V = 56 m/s
She maintains the speed through out the journey.
Speed = distance/time
Make time the subject of formula
Time = distance/speed
Time = 200 / 56
Time = 3.57s
Therefore, she will complete the race by 7 + 3.6 = 10.6 s
