Answer: He must drive at 58.8mi/hr
{3 significant figure}
Explanation: The original speed of the car to complete the journey normally is = 550mile/10hr
= 55mi/hr
The normal time to cover 120 mile with that speed is
t = distance/speed
= 120/55
=2hr, 0.18*60=11mins
= 2hr11mins.
But the driver found out he was 30mins behind at this distance, so he spent
2hr 11min +30min= 2hr41mins
For him to meet up the original schedule time 10hrs, he has
(10-2.41)hrs = 7hr19mins to cover the remaining distance of
{550-120}=430mile.
First, 7hr19mins= {7*(19/60)}hr
= {439/60}hr
Now let's find the speed at which the driver must move for him to cover for his initial delay
Speed= distance/time
= 430/{439/60}
This is same as writing
Speed = 430/439/60
Using the law of reciprocal,
Speed = (430*60)/439
= 25800/439
= 58.7699mi/hr
But we were asked to leave our answer in 3 significant figure. Therefore,
Speed = 58.8mi/hr
The process is called Eutrophication, the two main nutrients that cause eutrophication are nitrogen and phosphorus
Explanation:
Draw a free body diagram of the toolbox. There are two forces:
Weight force mg pulling down,
and applied force F pulling up.
Sum of forces in the y direction:
∑F = ma
F − mg = ma
45 N − 15 N = (3 kg) a
a = 10 m/s²
The answer should be B. It's possible the answer key has a mistake.
Answer:
Change in mechanical energy, 
Explanation:
It is given that,
Mass of the projectile, m = 12 kg
Speed of the projectile, v = 20 m/s
Maximum height, h = 18 m
Initially, the projectile have only kinetic energy. it is given by :
K = 2400 J
Finally, it have only potential energy. it is given by :
P = mgh
P =2116.8 J
The change in mechanical energy is given by :
So, the change in mechanical energy is 283.2 J. Hence, this is the required solution.
