Answer:
39.2m/s
Explanation:
Given parameters:
Mass of book = 5kg
Time taken for fall = 4s
Unknown:
Final velocity of the book = ?
Solution:
Serena dropped the book from rest therefore, the initial velocity of the book is 0.
Let us find the appropriate motion equation to solve this problem;
V = U + gt
V is the final velocity
U is the initial velocity
g is the acceleration due to gravity = 9.8m/s²
t is the time taken
Insert the given parameters and solve;
V = 0 + 9.8 x 4 = 39.2m/s
Answer:Sometime decreases and sometime increases.
Explanation:
Given
Projectile is launched at 
so horizontal velocity=ucos35
vertical velocity=usin35
since gravity acts in the vertical direction, therefore, it affects only the vertical component of the projectile.
So Vertical velocity first decrease up to maximum height and then starts to increase.
Answer:
Hey buddy, here is your answer. Hope it helps you.
Explanation:
Solids.Sound travels fastest through solids. This is because molecules in a solid are packed against each other. When a vibration begins, the molecules of a solid immediately collide and the compression wave travels rapidly.Sound moves slowest through a gas. That’s because the molecules in a gas are spaced very far apart. In order for sound to travel through air, the floating molecules of matter must vibrate and collide to form compression waves. Because the molecules of matter in a gas are spaced far apart, sound moves slowest through a gas.
Sound travels faster in liquids than in gases because molecules are packed more closely together. This means that when the water molecules begin to vibrate, they quickly begin to collide with each other forming a rapidly moving compression wave.
Velocity = displacement / time
v = 400 / 2
v = 200 km/h
In short, Your Answer would be 200 km/h
Hope this helps!
