Answer:
Explanation:
Solution is in the picture attached
Answer:
Focal Length = 38.61cm, Power = 2.59 Diopter, Converging lens.
Explanation:
When an object is placed 25cm from Gbenga's eye, the glasses lens must produce an image 61cm away (Gbenga's eye near point).
An image 61cm from the eye will be (61cm - 1.6cm) from the glasses.
i.e.
and 
note
will be negative because the image is formed on the same side as the object.
finally, 
the formula for finding the focal length
is given as




The focal length is positive which indicates converging lens
power 
but
must be in metres
Therefore, 


Answer:
The current in the rods is 171.26 A.
Explanation:
Given that,
Length of rod = 0.85 m
Mass of rod = 0.073 kg
Distance 
The rods carry the same current in the same direction.
We need to calculate the current
I is the current through each of the wires then the force per unit length on each of them is
Using formula of force


Where, m = mass of rod
l = length of rod
Put the value into the formula




Hence, The current in the rods is 171.26 A.
Answer:
26.2 m/s
Explanation:
We can find the speed of the cannonball just by analyzing its vertical motion. In fact, the initial vertical velocity is
(1)
where u is the initial speed and
is the angle of projection.
We can therefore use the following suvat equation for the vertical motion of the ball:

where
is the vertical velocity at time t, and
is the acceleration of gravity. The time of flight is 3.78 s, so we know that the ball reaches its maximum height at half this time:

And at the maximum height, the vertical velocity is zero:

Substituting these values, we find the initial vertical velocity:

And using eq.(1) we now find the initial speed:
