B. the reason we must wear seat belts
Answer:
1 sec
Explanation:
Horizontal distance (x) = 6m
Vertical distance (y) = 1.25m
Hang time is the duration the object is in the air before it reaches maximum height.
The time of free fall is given by
t = √2y/g
g = acceleration due to gravity
t = √(2*1.25)/9.8
t = √2.5/9.8
t = 0.5secs
Hang time = 2*0.5
= 1 sec
So this is dealing with the conservation of energy. So you set kinetic energy equal to potential energy, so it looks like this:
1/2mv^2=mgh. The m's cancel out, so it is 1/2v^2=gh.
To find out what the height h is, divide g on both sides, so...
h=0.5v^2/g. v=22m/s, g=9.81m/s^2, so h=(0.5)(22^2)/(9.81)=24.67m
Answer:
The image distance is 30 cm
image height = - 5 cm
Explanation:
The formula for calculating the image distance is expressed as
1/f = 1/u + 1/v
where
f is the focal length
u is the object distance
v is the image distance
From the information given,
u = 30
f = 15
By substituting these values into the formula,
1/15 = 1/30 + 1/v
1/v = 1/15 - 1/30 = (2 - 1)/30 = 1/30
Taking the reciprocal of both sides,
v = 30
The image distance is 30 cm
magnification = image height/object height = - v/u
Given that object height = 5 cm, then
image height/5 = - 30/30 = - 1
image height = - 5 * 1
image height = - 5 cm
A liquid is a matter that neither has a fixed shape but fixed volume...in college really need to know this.
GOOD LUCK
