Given conditions:
height of object = 7.5cmdistance of object from mirror = 14 cmfocus length = -7 cmimage distance = ?
Using mirror formula:
1/(focus length) = 1/(object distance) + 1/(image distance)
or, -1/7 = 1/14 + 1/(image distance)
or, image distance = -4.66cm (the image formed is a virtual image)
Also, magnification of image is:
image height /height of object = - image distance /object distance
or, image height = - image distance / object distance * height of object
or, image height = -(-4.66) / 14 * 7.5 = 2.49 = 3(nearest whole number)
The stone will take 2.89 seconds to hit the water.
The time required by the stone to hit the water is calculated by the second equaiton of motion
s=ut+
gt^2
41=0×t+
×9.81×t²
t=2.89 seconds
Answer:
41.02m
Explanation:
Given parameters:
Initial velocity = 0m/s
Final velocity = 96km/hr
Time taken = 3.07s
Unknown:
Distance traveled by the time the final speed was achieved = ?
Solution:
To solve this problem, we first find the acceleration of the car;
Acceleration =
v is the final velocity
u is the initial velocity
t is the time taken
Now convert the the final velocity to m/s;
96km/hr to m/s;
1 km/hr = 0.278m/s
96km/hr = 96 x 0.278 = 26.7m/s
Now;
Acceleration =
= 8.69m/s²
So;
v² = u² + 2as
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance
26.7² = 0² + 2 x 8.69 x s
712.89 = 17.38s
s = 41.02m