Answer:
A. 10 joules
Explanation:
Given parameters:
Mass of object = 4kg
Speed = 5m/s
Unknown:
Kinetic energy of the the object = ?
Solution:
Kinetic energy is the energy due to a moving body.
So;
mathematically;
K.E = 
x m v²
m is the mass
v is the velocity
K.E = x 4 x 5 = 10J
The image is present at 20cm from the crown glass spherical surface.
To find the answer, we need to know about the lens formula.
<h3>
What's the lens formula?</h3>
- It's (1/V)-(1/U)= (1/f)
- V= image distance from the lens, U= object distance, f= focal length of the lens
<h3>What's the image distance, if object is present at 20cm from crown glass of power 10DS?</h3>
- Focal length (f)= 1/ power = 1/10 = 0.1 m
- U= -20cm = -0.2m (-ve sign due to sign convection)
- (1/V)-(-1/0.2)= (1/0.1)
=> (1/V)+5=10
=> 1/V= 5
=> V=0.2m = 20cm
Thus, we can conclude that the image is present at 20cm.
Learn more about the lens formula here:
brainly.com/question/2098689
#SPJ1
Not so fast.
I think you're using 'accelerating' to mean 'speeding up', but you really need
to be more careful with it. "Acceleration" means ANY change in speed OR
direction.
If an object's speed to the left is decreasing, or its speed to the right is
increasing, then the net force on the object must be directed towards
the right.
If an object is moving with constant speed in a circular path, then it's
constantly accelerating, because its direction is constantly changing.
The force on it is always directed towards the center of the circle, so
there's one point on the path where the force is directed straight to the right.
