Let <em>b</em> be the height of the building, and <em>y</em> the height of the ball at time <em>t</em>, given by
<em>y</em> = <em>b</em> - 1/2 <em>gt</em>²
where <em>g</em> = 9.8 m/s² is the magnitude of the acceleration due to gravity.
It takes the ball 8 s to reach the ground, at which point <em>y</em> = 0, so that
0 = <em>b</em> - 1/2 (9.8 m/s²) (8 s)²
<em>b</em> = 1/2 (9.8 m/s²) (8 s)²
<em>b</em> = 313.6 m

Here's the solution ~
As we know, Displacement =



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The car travelled 1700 meters ( 1.7 km )
Answer:
Explanation:
Givens
Heat of Fusion = 2.05 * 10^5 J / kg watch the units.
Heat to actually melt the copper = 82 10^5 J
Formula
Mass of copper = Heat / Heat of Fusion
Solution
Mass of copper = 82*10^5 J / (2.05 * 10^5 J / kg)
Mass of copper = 40 kg
Notice that the kg is in the denominator of the second fraction. The rules of fractions would tell you the 1/1 / / 1 /kg . You take the right fraction and turn it upside down and multiply. 1 / 1 * kg/1 = 1* kg / 1*1 which is just kg.
Answer 40 kg of copper
Answer:
<em>radius of the loop = 7.9 mm</em>
<em>number of turns N ≅ 399 turns</em>
Explanation:
length of wire L= 2 m
field strength B = 3 mT = 0.003 T
current I = 12 A
recall that field strength B = μnI
where n is the turn per unit length
vacuum permeability μ =
= 1.256 x 10^-6 T-m/A
imputing values, we have
0.003 = 1.256 x 10^−6 x n x 12
0.003 = 1.507 x 10^-5 x n
n = 199.07 turns per unit length
for a length of 2 m,
number of loop N = 2 x 199.07 = 398.14 ≅ <em>399 turns</em>
since there are approximately 399 turns formed by the 2 m length of wire, it means that each loop is formed by 2/399 = 0.005 m of the wire.
this length is also equal to the circumference of each loop
the circumference of each loop = 
0.005 = 2 x 3.142 x r
r = 0.005/6.284 =
= 0.0079 m =<em> 7.9 mm</em>
Answer:
The magnitude of electrostatic force on each charge is quarter of the magnitude of initial electrostatic force. ( ¹/₄ F)
Explanation:
The electrostatic force between two charges is given by Coulomb's law;

where;
Q₁ and Q₂ are the magnitude of the charges
r is the distance between the charges
k is Coulomb's constant
Since the charges are identical;
Q₁ = Q
Q₂ = Q
the electrostatic force experienced by each charge is given by;

When each of the spheres has lost half of its initial charge;
Q₁ = Q/2
Q₂ = Q/2

Therefore, the magnitude of electrostatic force on each charge is quarter of the magnitude of initial electrostatic force.