Answer:
Explanation:
Average speed is given by
Total distance/ total time taken
So we need to know the distance in the first travel
Then
First part
Speed=60miles/hour
Time 3hours
Distance = speed × time
Distance = 60×3
Distance = 180 miles
Second part
Speed 45mile/hour
And time is 2hours
Distance = speed × time
Distance = 45× 2
Distance = 90miles
So total distance travelled for both cases is 90+180=270miles
And total time is 5hours
Then,
Average speed = total distance/total time
A.S=270/5
A.S= 54miles/hour
The impulse-momentum theorem
Planets, Sun, stars, plasma, and black matter
Answer:The gravitational field on Saturn can be calculated by the following formula;
Explanation:
Answer:
Vf = 210 [m/s]
Av = 105 [m/s]
y = 2205 [m]
Explanation:
To solve this problem we must use the following formula of kinematics.

where:
Vf = final velocity [m/s]
Vo = initial velocity = 0 (released from the rest)
g = gravity acceleration = 10 [m/s²]
t = time = 21 [s]
Vf = 0 + (10*21)
Vf = 210 [m/s]
Note: The positive sign for the gravity acceleration means that the object is falling in the same direction of the gravity acceleration (downwards)
The average speed is defined as the sum of the final speed plus the initial speed divided by two. (the initial velocity is zero)
Av = (210 + 0)/2
Av = 105 [m/s]
To calculate the distance we must use the following equation of kinematics

44100 = 20*y
y = 2205 [m]