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:
work done = force x distance
Explanation:
F = 23 N
D = 2m
W = 23 * 2 = 46 J
E = hf
E = 6.63* 10 ⁻³⁴ * 7.24* 10¹⁴
<span>E = 4.80012 × 10⁻¹⁹ J</span>
Answer:
The maximum height of ball 2 is 4 times that of ball 1
Explanation:
We can find the maximum height of each ball by using the following suvat equation:

where
v is the final velocity
u is the initial velocity
is the acceleration of gravity (we take upward as positive direction)
s is the displacement
At the maximum height, s = h and v = 0 (the final velocity is zero), so re-arranging the equation:

The first ball is thrown with initial velocity
, so it reaches a maximum height of
(the quantity will be positive, since g is negative)
The second ball is thrown with initial velocity

so it will reach a maximum height of

So, its maximum height will be 4 times the maximum height reached by ball 1.