To solve the exercise it is necessary to take into account the definition of speed as a function of distance and time, and the speed of air in the sound, as well

Where,
V= Velocity
d= distance
t = time
Re-arrange the equation to find the distance we have,
d=vt
Replacing with our values


It is understood that the sound comes and goes across the entire lake therefore, the length of the lake is half the distance found, that is



Therefore the length of the lake is 634,55m
Answer:
B. Glass
Explanation:
An electrical insulator is a substance that does not conduct electricity.
Glass has tightly bounded electrons, that is why it is an insulator of electricity.
Answer:
a) 1.22 s
b) 9.089 m
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²

Time taken by the ball to reach the highest point is 1.22 seconds

The maximum height the ball will reach above the ground is 1.75+7.339 = 9.089 m
Explanation:
Kinetic energy (J) = 2j
mass= 250g
velocity=?
1kg=1000g
mass= 250/1000
mass=0.25kg
Kinetic energy (J) = ½ x mass (kg) x [velocity]² (m/s)
2=1/2 × 0.25× [velocity]²
2=0.125× [velocity]²
[velocity]² = 2/0.125
[velocity]²=16
velocity= (16)^1/2
velocity= 4 m/s