Answer:
Explanation:
Given
Distance to grandmother's house=100 mi
it is given that during return trip Julie spend equal time driving with speed 30 mph and 70 mph
Let Julie travel x mi with 30 mph and 100-x with 70 mph
x=30 mi
Therefore
Julie's Average speed on the way to Grandmother's house
=42 mph
On return trip
The rule to get the average speed is as follows:
average speed = average distance / average time
We are given that:
distance = 250 m
time = 110 sec
Substitute with the givens in the above equation to get the average speed as follows:
average speed = 250/110 = 25/11 meters/sec
Answer:
- <u>77.8 m/s, downward</u>
Explanation:
For uniform acceleration motion, the average speed is equal to half the soum of the initial velocity, Vi, and the final velocity, Vf
- Average speed = (Vf + Vi)/2
Also, by definition, the average speed is the distance divided by the time:
- Average speed = distance / time
Then:
Other kinematic equation for uniform acceleration is:
Since the window is falling and the air resistance is ignored, a = g (gravitational acceleration ≈ 9.8m/s²)
Replacing the known values we can set a system of two equations:
From (Vf + Vi)/2 = 300m/6.62s
(Vf + Vi) = 2 × 300m/6.62s
- Vf + Vi = 90.634 equation 1
From Vf = Vi + a×t
Vf - Vi = 9.8 (6.62)
- Vf - Vi = 64.876 equation 2
Adding the two equations:
- Vf = 77.8 m/s downward (velocities must be reported with their directions)
Answer:
y = 43.55 + 2.15t
Explanation:
We were told that in 1983, the per capita consumption was 37.1 pounds, and in 1989 it was 50 pounds.
If we assume t = 0 corresponds to year 1980. Then, for 1983 it will be t = 3 and for 1989,it will be t = 9.
Thus, expressing the information as ordered pairs, we have; (3,37. 1) and (9,50).
Let us now find slope of the linear function:
m1 = (y2 - y1)/(t2 - t1)
m1 = (50 - 37.1)/(9 - 3)
m1 = 2.15
So, we can find the linear equation as;
y - 37.1 = 2.15(t - 3)
y = 37.1 + 2.15t - 6.45
y = 43.55 + 2.15t
