Answer:
the answer is at
Explanation:
Dimension of at = [ LT^-2 ] [ T ]
= [ LT^(-2+1) ]
= [ LT^-1 ]
which is same as dimension of speed.
Answer:
All of them: change velocity, accelerate, change position
Explanation:
We can answer this question by using Newton's second law:
F = ma
where
F is the net force on the object
m is the mass of the object
a is the acceleration
We notice that when there is an unbalanced force on the object,
, and therefore

whcih means that the object will accelerate.
But acceleration is the rate of change of velocity, v:

And so,

which means that the object will change velocity.
If the object is changing velocity, this means that it is also moving: therefore, the position of the object must be changing, so also the option "change position" is correct.
Answer:
length of selfie-stick is 1.62 m
Explanation:
Given data
image size h1 = 5 mm = 5 ×
m
focal length = 4 mm = 4 ×
m
distance h2 = 2.032 m
to find out
How long of a selfie-stick
solution
here we find first magnification
that is M = h1 /h2
M = 5 ×
/ 2.032
M = 2.46 ×
and we know M = p/q
so p = Mq = 2.46 ×
q
so we apply lens formula
1/f = 1/p - 1/q
1/ 4 ×
= 1 / 2.46 ×
q - 1/q
q = 1.622 m
so length of selfie-stick is 1.62 m