Answer:
i think its the third one or second one
Explanation:
Since its accelerating, the velocity vs time graph is linear
For displacement we need initial velocity (which is zero because it starts from rest) and final velocity (which is calculatee thro acceleration formula
A= (vf - vi)/t
a= vf-0/t
1.25=vf / 7
1.25*7=vf
8.75 = vf
Now for displacement plug all the values in
X = 1/2(vf-vi)/t formula
The displacement (x) is 30.625 m
For part 3, we know new displacement that is 22m , the final and initial velocities are the same so just plug in the values for same formula above
The answer is t = 5.02
Im pretty sure all the answers are correct
Answer:
what this please be clear
Answer:
The focal length of the concave mirror is -15.5 cm
Explanation:
Given that,
Height of the object, h = 20 cm
Radius of curvature of the mirror, R = -31 cm (direction is opposite)
Object distance, u = -94 cm
We need to find the focal length of the mirror. The relation between the focal length and the radius of curvature of the mirror is as follows :
R = 2f
f is the focal length
f = -15.5 cm
So, the focal length of the concave mirror is -15.5 cm. Hence, this is the required solution.
Divide the distance by the speed:
(18 m) / (42 m/s) = 3/7 s ≈ 0.43 s
