Answer:
A)s = 104.16 m
b)s= 104.16 m
Explanation:
Given that
u = 25 m/s
μ = 0.3
The friction force will act opposite to the direction of motion.
Fr= μ m g
Fr= - m a
a=acceleration
μ m g = - m a
a= - μ g
a= - 0.3 x 10 m/s² ( take g= 10 m/s²)
a= - 3 m/s²
The final speed of the mass is zero ,v= 0
We know that
v² = u² +2 a s
s=distance
0² = 25² - 2 x 3 x s
625 = 6 s
s = 104.16 m
By using energy conservation
Work done by all the forces =Change in the kinetic energy
Negative sign because force act opposite to the displacement.
- 3 x 2 x s = - 625
s= 104.16 m
1) v = gt = 10*1.5 = 15 m/s
2) r = gt^2 /2 = 10*(1.5)^2 / 2 = 11.25 meters
<span>Th find the average speed of a trip we need to dived the total distance by the total time.
Let's find the total distance d.
d = (300 mi/h)(2.00 h) + 750 miles
d = 600 miles + 750 miles
d = 1350 miles
The total distance is 1350 miles
Let's find the total time t.
t = 2.00 hours + (750 mi / 250 mi/h)
t = 2.00 hours + 3.00 hours
t = 5.00 hours
The total time of the trip is 5.00 hours.
We can find the average speed.
d / t = 1350 miles / 5.00 hours
d / t = 270 miles/ hour
The average speed of the trip is 270 mi/h
(Note that the direction does not matter when we find the average speed.)</span>
