Consider the motion of the car before brakes are applied:
v₀ = maximum initial velocity of the car before the brakes are applied
t = reaction time = 0.50 s
x₀ = distance traveled by the car before brakes are applied
since car moves at constant speed before brakes are applied
Using the equation
x₀ = v₀ t
x₀ = v₀ (0.50)
Consider the motion after brakes are applied :
v₀ = initial velocity of the car before the brakes are applied
a = acceleration = - 10 m/s²
v = final velocity of the car after it comes to stop = 0 m/s
x = stopping distance = initial distance - distance traveled before applying the brakes = 38 - x₀ = 38 - v₀ (0.50)
Using the equation
v² = v²₀ + 2 a x
inserting the values
0² = v²₀ + 2 (- 10) (38 - v₀ (0.50))
v²₀ = 20 (38 - v₀ (0.50))
v₀ = 23 m/s
Answer:
B
Explanation:
a force acting upon an object increases that objects acceleration
Answer:
A measurement standard is a quantity that people agree to use as a comparison. Standards are important because they allow measurements to be compared even if different people in different parts of the world take them.
Hope this helps ⊂◉‿◉つ
Answer:
Explanation:
As the source is situated on x - axis , it must be situated in between the two listeners .
So the x coordinate of source is
(-7 + 3 )/2
= - 2 m
The equation of the wave- front will be that o a circle having centre at (-2,0)
and radius = distance between -2 and 3 , that is 5 m
equation of circle
=( x+2 )² + y² = 25
It cuts y axis when x = 0
Putting x = 0
4 + y² = 25
y² = 21
y = + √21 , or - √21