Answer:
Explanation:
L = Initial length of segment = 79 m
T = Normal temperature =
l = Width to be left for expansion
= Coefficient of linear expansion of the material =
= Maximum temperature =
= Change in temperature =
The expression of linear expansion is given by
The expression for the minimum gap distance l the engineers must leave for a track rated at temperature is
Answer:
v’ =( ) v
we see that the greater the difference, the more the sled slows down.
friction force
Explanation:
When the man pushes the sled he does work and the sled acquires a speed and as long as it is supplied with an energy equal to the work of the chipping force with the snow, the speed is maintained.
When he jumps on the sled, a collision occurs and the initial moment
p₀ = mv
is increased by the increase in mass
m_f= (m + M_{man} ) v '
In this case there is no longer any external force applied and the only external force is friction, which causes the sled to stop, even when it is small, but the significant reduction in speed is due to the increase in masses.
p₀ = p_f
mv = (m + M_{man}) v '
v ’= v
v’ =( ) v
Therefore, we see that the greater the difference, the more the sled slows down.
The only forces that act on the sled with the man are the friction that is responsible for the decrease in speed and weight with the normal