Answer:

Explanation:
As we know that thermal expansion coefficient of aluminium is given as

now we also know that after thermal expansion the final length is given as

here we know that



now we will have


#2
As it is given here
initial speed is

After 4 seconds the final speed is

so here we can use the formula of acceleration using kinematics



so here it will accelerate at 2 m/s^2 rate.
#3
As it is given here
initial it starts from rest

After 2.5 seconds the final speed is

so here we can use the formula of acceleration using kinematics



so here it will accelerate at 6 m/s^2 rate.
#4
i think question is not correct as in first line it is saying about a bag of trash and then in next line it is asking for the position of Jumper and bridge.
Increasing the temperature causes an increase in the average kinetic energy of the particles of a material.
<h3>
What is average kinetic energy of particles?</h3>
The average kinetic energy of particles is the energy possessed by particles due to their constant motion.
The constant motion of particles occurs due to the energy acquired by the particles, when the temperature of the particles increases, the average kinetic energy increases which in turn increases the speed of the particles.
Thus, we can conclude that, increasing the temperature causes an increase in the average kinetic energy of the particles of a material.
Learn more about average kinetic energy here: brainly.com/question/9078768
A pure substance that is made up of only one kind of atom is called an element