Considering the definition of speed, the speed of Sam is 3.6 
.
<h3>Definition of speed</h3>
Speed is a quantity that expresses the relationship between the space traveled by an object. That is, the speed is associated with the change of position of an object in space within a certain amount of time.
The speed can be calculated using the expression:
<h3>Speed of Sam</h3>
In this case, you know:
- displacement= 9 km
- time= 2.5 h
Replacing in the definition of speed:
Solving:
<u><em>speed= 3.6 </em></u>
Finally, the speed of Sam is 3.6 .
Learn more about speed:
brainly.com/question/13803208
brainly.com/question/20725831
#SPJ1
Answer:
From lowest to highest acceleration:
3rd train
2nd train
1st train
Explanation:
The acceleration of an object can be found by using Newton's second law:
where
a is the acceleration
F is the net force on the object
m is the mass of the object
We notice that for equal values of the forces F, the acceleration a is inversely proportional to the mass, m. Therefore, greater mass means lower acceleration, and viceversa.
So, the train with lowest acceleration is the one with largest mass, i.e. the 3rd train consisting of 50 equally loaded freight cars. Then, the 2nd train has larger acceleration, since it consists of 50 empty freight cars (so its mass is smaller). Finally, the 1st train (a single empty car) is the one with largest acceleration, since it is the train with smallest mass.
Answer:
Net force ( F ) = 208 N.
Speed of car ( v ) = 68.58 m/s.
Explanation:-
The radius ( r ) = 480 m.
Mass of passenger ( m ) = 65 kg.
Horizontal force ( 
) = 208 N.
Vertical force ( 
) = 637 N.
Net vertical component of force ( ) = m*g - 637 = 65 * 9.8 - 637 = 0 N.
a ) magnitude of net force .
= 208 N.
b) The speed of car.
where v is the velocity.
v² = 4704
v = 68.58 m/s.
Answer:
the slope of velocity-time graph represent an object acceleration
