A diver wants to jump from a board, the initial height is 10 meters and he wants to reach a horizontal distance of 2 meters. Wha
1 answer:
You might be interested in
Answer:
= 3.8 m/s
Explanation:
When the runner start the running, she is at rest. So the initial velocity of the runner is zero (0 m/s). And then she accelerates at a rate of 1.9 m/s² for 2.2 s. But we need to find the final velocity after t = 2 s when she starts the running. So, we take time equal to 2 second.
Given data:
Initial velocity = = 0 m/s
Acceleration = a = 1.9 m/s² (for 2.2 s after starting the race)
Time = t = 2 s
Final velocity = = ?
According to the First equation of motion
=
+ at
= 0 + (1.9)(2)
= 3.8 m/s
Answer:
30 cm
Explanation:
To solve this problem, we use the lens equation:
where
f is the focal length of the lens
p is the distance of the object from the lens
q is the distance of the image from the lens
In this problem, we know that
q = -30 cm is the distance of the image from the lens; it is negative because the image is formed in front of the lens, so it is a virtual image
We also know that the size of the image is twice that of the object, so the magnification is 2:
where M is the magnification of the lens. Solving this equation for p,
So, the distance of the object from the lens is 15 cm.
Now we can finally solve the lens equation to find f, the focal length: