Answer:
The acceleration of the crate is 
Explanation:
Recall the formula that relates force,mass and acceleration from newton's second law;

Then in our case, we know the force applied and we know the mass of the crate, so we can solve for the acceleration as shown below:

A ) decrease.
B ) increase.
C ) increase, then decrease.
D ) not change.
The answer is A) decrease
Take pushing a box, for example-- You push your hardest then give out, still trying to push the box. You are doing less work than what you have started with!
( Mind marking me for branliest? ; ) )
Work with your units:
1 watt-hour = 1 (joule/second) · (hour) = 1 (joule-hour / second)
(1 joule-hour/sec) · (3600 sec/hour) = 3600 joules
So 1 watt-hour = 3,600 joules
Answer:
15.8 ft/s
Explanation:
= Velocity of car A = 9 ft/s
a = Distance car A travels = 21 ft
= Velocity of car B = 13 ft/s
b = Distance car B travels = ft
c = Distance between A and B after 4 seconds = √(a²+b²) = √(21²+28²) = √1225 ft
From Pythagoras theorem
a²+b² = c²
Now, differentiating with respect to time

∴ Rate at which distance between the cars is increasing three hours later is 15.8 ft/s
Your answer would be C, with a quick lookup of this question online lol