I GEUSS A and COM is correct answer to this question
Answer:
12.5 m/s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 0 m/s
Height (h) = 8 m
Final velocity (v) at 8 m above the lowest point =?
NOTE: Acceleration due to gravity (g) = 9.8 m/s²
The velocity of the roller coaster at 8 m above the lowest point can be obtained as follow:
v² = u² + 2gh
v² = 0² + (2 × 9.8 × 8)
v² = 0 + 156.8
v² = 156.8
Take the square root of both side
v = √156.8
v = 12.5 m/s
Therefore, the velocity of the roller coaster at 8 m above the lowest point is 12.5 m/s.
Answer:
120 miles per hour.
Explanation:
We need to find the time it takes my parents to drive home from the cottage. Since my father drives at 60 miles per hour, and the cottage is 240 miles from our home, and distance = speed × time. So, time = distance/speed = 240 mi/60 mi/h = 4 h.
So, it will take my father 4 hours to drive home from the cottage.
Since I have 2 hours to prepare for the party, the time left for me to drive to the cottage is 4 - 2 hrs = 2 hrs.
So, I'm supposed to drive to the cottage in at most 2 hours.
The speed at which I must drive in this time period is thus, speed = distance/time = 240 miles/2 hours = 120 miles per hour.
So, I must drive at a minimum speed of 120 miles per hour.
Answer:
3.5 hours
Explanation:
Speed = distance/time
Let the distance that Fiora biked at 20 mi/h through be x miles and the time it took her to bike through that distance be t hours at 20 mi/h
Then, the rest of the distance that she biked at 14 mi/h is (112 - x) miles
And the time she spent biking at 14 mi/h the rest of the distance = (6.5 - t) hours
Her first biking speed = 20 mph = 20 miles/hour
Speed = distance/time
20 = x/t
x = 20 t (eqn 1)
Her second biking speed = 14 mph = 14 miles/hour
14 = (112 - x)/(6.5 - t)
112 - x = 14 (6.5 - t)
112 - x = 91 - 14t (eqn 2)
Substitute for x in (eqn 2)
112 - 20t = 91 - 14t
20t - 14t = 112 - 91
6t = 21
t = 3.5 hours
x = 20t = 20 × 3.5 = 70 miles.
(112 - x) = 112 - 70 = 42 miles
(6.5 - t) = 6.5 - 3.5 = 3 hours
Meaning that she travelled at 20 mi/h for 3.5 hours.
Answer:
0.85 c
Explanation:
When the two travel at right angles to each other , their relative velocity is given by the hypotenuse formed by the x and y direction velocities.
Relative velocity of the two protons is given as

If v = 3/5 c , then the relative speed =
(3/5c) =0.85 c