A device used to initiate and control a sustained nuclear chain reaction.
Answer : Option B) Perfect Circles
Explanation : In heliocentric model where sun is considered to be the center and earth and other planets revolves around it. The shape of the objects in the space is perfectly circle as they move around the sun.
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:
Answer:
133.62 kmh.
Explanation:
Time provided = 3.25 hours.
Distance to be covered 300 km
Times spent in first 100 km = 1 hour
Time spent in next 43 km
= 43 / 40 = 1.075 hours
Total time spent = 2.075 hours
Total distance covered = 143 km
Distance remaining = 300 - 143
=157 km .
Time remaining = 3.25 - 2.075
= 1.175
Speed required = Distance remaining / time remaining
= 157 / 1.175
= 133.62 kmh.
