Answer:
10kg
Explanation:
Let PE=potential energy
PE=196J
g(gravitational force)=9.8m/s^2
h(change in height)=2m
m=?
PE=m*g*(change in h)
196=m*9.8*2
m=10kg
Answer:
Since light travels faster than sound, the lightning arrives before the thunder. But thunder is the sound of lightning shooting through the sky in a thunderstorm.
Explanation:
Answer:
b. 
Explanation:
As we know that the electric field due to infinite line charge is given as

here we can find potential difference between two points using the relation

now we have

now we have

now plug in all values in it


now we know by energy conservation


Answer:
U = √Rg/sin2θ
Explanation:
Using the formula for "range" in projectile motion to derive the average speed before the ball hits the ground.
Range is the distance covered by the body in the horizontal direction from the point of launch to the point of landing.
According to the range formula,
R = U²sin2θ/g
Cross multiplying we have;
Rg = U²sin2θ
Dividing both sides by sin2θ, we have;
U² = Rg/sin2θ
Taking the square root of both sides we have;
√U² = √Rg/sin2θ
U = √Rg/sin2θ
Therefore, his average speed if he is to meet the ball just before it hits the ground is √Rg/sin2θ
Answer:
there are 2188 people at the game
Explanation:
Given the data in the question;
we know that decibel is defined as; dB = 10log(l/l₀)
so if one produces an intensity l₁, it results in 69.6 dB
69.6 = 10log(l₁/l₀) ---- equ1
also. if x number of people produces this intensity, it result to 103 dB
103 = 10log(xl₁/l₀)
103 = 10( log(l₁/l₀) + log(x) )
103 = 10log(l₁/l₀) + 10log(x) ----- equ2
input equation 1 into to equation 2
103 = 69.6 + 10log(x)
10log(x) = 103 - 69.6
10log(x) = 33.4
divide both side by 10
log(x) = 3.34
x = 
x = 2187.76 ≈ 2188
Therefore, there are 2188 people at the game