Answer:
8.5 m/s
Explanation:
please see paper for the work!
Thermal energy is an example of kinetic energy<span>, as it is due to the motion of particles, with motion being the key. Thermal energy results in an object or a system having a temperature that can be measured. Thermal energy can be transferred from one object or system to another in the form of heat.</span>
by the formula
s=d/t
speed=distance/time
the bigger the distance that has been traveled over a period of time the bigger the speed
Answer:
The critical stress required for the propagation of an initial crack 
= 21.84 M pa
Explanation:
Given data
Modulus of elasticity E = 225 × 
Specific surface energy for magnesium oxide is 
= 1 
Crack length (a) = 0.3 mm = 0.0003 m
Critical stress is given by 
= 
-------- (1)
⇒ 2 E = 2 × 225 × × 1 = 450 ×
⇒ 
a = 3.14 × 0.0003 = 0.000942
⇒ Put these values in equation 1 we get
⇒ = 
⇒ = 4.77 × 
⇒ = 2.184 × 
⇒ = 21.84 
⇒ = 21.84 M pa
This is the critical stress required for the propagation of an initial crack.
Answer:
I think they use it at night because they want to avoid involving themselves in road accident while crossing the street. When there are reflective strips on their clothes, drivers do notice them even at far ends of the street since the strips will reflect the rays from the car lights to the driver,hence, the driver notifies that there is a pedestrian crossing and therefore slows down.
