If the velocity is constant then the acceleration of the object is zero.

Thus when we apply the equation

It remains

or equivalent
Answer:
4.2 m
Explanation:
Note: If energy is conserved, i.e no work is done against friction
Work input = work output.
Work output = Force output × distance,
Work input = force input × distance moved moved.
Therefore,
input force×distance moved = output force × distance moved........................Equation 1
Given: input force = 80 N, output force = 240 N, output distance = 1.4 m
Let input distance = d
Substitute into equation 1
80×d = 240×1.4
80d = 336
d = 336/80
d = 4.2 m.
Thus the rope around the pulley must be pulled 4.2 m
Answer:
a)
b)S= 46.4 cm
Explanation:
Given that
Velocity = 16 Km/s
V= 16,000 m/s
E= 27 mV/m
E=0.027 V/m
d= 22.5 cm
d= 0.225 m
a)
lets time taken by electron is t
d = V x t
0.225 = 16,000 t

b)
We know that
F = m a = E q ------------1
Mass of electron ,m

Charge on electron

So now by putting the values in equation 1




Here initial velocity u= 0 m/s

S=0.464 m
S= 46.4 cm
S is the deflection of electron.
Answer:

Explanation:
The apparent brightness follows an inverse square law, therefore we can write:

where I is the apparent brightness and r is the distance from the Sun.
We can also rewrite the law as
(1)
where in this problem, we have:
apparent brightness at a distance
, where
million km
We want to estimate the apparent brightness at
, where
is ten times
, so

Re-arranging eq.(1), we find
:
