I think it false. Sorry if i'm wrong.
B. +Q, + W are the correct sign
Answer:
yes
Explanation:
objects with constant velocity also have zero net external force. this means the forces on the object are balanced. this mean they are in equilibrium
Given the distance traveled and time elapsed, the average speed of the train is approximately 26.944m/s.
<h3>What is the average speed of the train?</h3>
Speed is simply referred to as distance traveled per unit time.
Mathematically, Speed = Distance ÷ time.
Given the data in the question;
- Distance traveled = 221miles
- Elapsed time = 3 hours and 40 minutes
First we convert miles to meters and Hours minutes to seconds.
221 miles = ( 221 × 1609.344 )m = 355665.024 meters
3 hours and 40 minutes = ( 3×60×60)s + ( 40×60)s
= 10800s + 2400s
= 13200s
Now, determine the average speed.
Speed = Distance ÷ time
Speed = 355665.024m / 13200s
Speed = 26.944m/s
Given the distance traveled and time elapsed, the average speed of the train is approximately 26.944m/s.
Learn more about speed here: brainly.com/question/7359669
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Answer:
(a) -472.305 J
(b) 1 m
Explanation:
(a)
Change in mechanical energy equals change in kinetic energy
Kinetic energy is given by
Initial kinetic energy is 
Since he finally comes to rest, final kinetic energy is zero because the final velocity is zero
Change in kinetic energy is given by final kinetic energy- initial kinetic energy hence
0-472.305 J=-472.305 J
(b)
From fundamental kinematic equation
Where v and u are final and initial velocities respectively, a is acceleration, s is distance
Making s the subject we obtain
but a=\mu g hence
