Answer:

Explanation:
We are given that







We have to find the exit temperature.
By steady energy flow equation



Substitute the values




Answer:
yes
Explanation:
As the formula is α= ΔL/L*ΔT where alpha (α) is the sign of coefficient of linear expansion
Part A: a->positive when velocity is increasing a->negative when velocity is decreasing a->zero when velocity is constant
Answer:
B) Tommy had a positive acceleration between noon and 12:30 pm.
Explanation:
Acceleration is defined as the rate of change of velocity:

where
v is the final velocity
u is the initial velocity
t is the time
In the problem,
- At noon, Tommy is walking at a velocity of 4 mi/h
- At 12.30 pm, Tommy is walking at a velocity of 6 mi/h
- A time of half an hour (0.5 h) passed between the two moments
So Tommy's acceleration is

and the acceleration is positive, since the velocity has increased.
Explanation : If a bar magnet is suspended at the center on a string and allow to swing freely, then the magnet will rotate so that it will line with the pole of the earth .
So, we can say that when the magnet suspended freely by the string, then the magnet will rotate and stop in north and south direction . The north pole of the magnet will stop in the south direction of the earth and the south pole of the magnet will stop in the north direction of the earth.