Answer:
3.71 m/s
Explanation:
From the law of conservation of linear momentum, since we are neglecting minor energy losses due to friction then we can express it as 
since all the potential energy is transformed to kinetic energy
Making v the subject of the formula then 
and here m is the mass of the block, g is acceleration due to gravity, h is the height. Substituting 0.7 m for h and 9.81 for g then we obtain that 
Answer:
a. 
W
Explanation:
= temperature of the surface of sun = 5800 K
= Radius of the Sun = 7 x 10⁸ m
= Surface area of the Sun
Surface area of the sun is given as
= Emissivity = 1
= Stefan's constant = 5.67 x 10⁻⁸ Wm⁻²K⁻⁴
Using Stefan's law, Power output of the sun is given as
Since they do not stick after collision hence collision is elastic. In elastic collision, both momentum and kinetic energy is conserved because in this type of collision, first body deforms but then quickly regains its former shape and transfers its kinetic energy to the second pluck.
So kinetic energy is conserved.
To solve this problem we will apply the given concept for torque which explains the relationship between the force applied and the distance to a given point. Mathematically this relationship is given as
Where,
Torque
F = Force
d = Distance
Our values are given as,
Therefore replacing we have that the force is
F = 12.72N
Therefore the least amount of force that you must exert is 12.72N
The distance the object moved is 100 m
the power of the machine is 1000 watts
distance = work/force (because work = force x distance)
distance = 20000/200 = 100
power = work/ time
power = 20000/20 = 1000
