Answer:
Average speed in east direction
Explanation:
We have given average speed of the entire trip = 5 km/hr
First the car 4 hours then travels 12 km in 4 hours
So total time of the trip = 4+4 = 8 hours
So total distance traveled in the trip 
As the car travel 12 km in 4 hours to the west
So distance traveled in 4 hour in east = 40 -12 = 28 km
Time in east direction = 4 hour
So average speed in east direction 
Answer:

Explanation:
As we know that


also we know that

it is given as


also we can find the magnitude of two vectors as


similarly we have


now we know the formula of dot product as




The food you eat every day provides the nutrients you need to survive. These food components include the macronutrients – protein, carbohydrate and fat – that offer calories as well as play specific roles in maintaining your health. Micronutrients, such as vitamins and minerals, don’t act as an energy source but do serve a variety of critical functions to ensure your body operates as optimally as possible.
In order to find the force (F), you would have to use the formula for it:
F=ma
where m is mass and a is acceleration.
In the problem, the mass is 2.85kg and the acceleration is 4.9m/s^2.
Therefore,
F=2.85kg(4.9m/s^2)
F=13.965kg(m/s^2)
Since N=kg(m/s^2)
F=13.965N
And because the problem requires that we use only 2 significant figures,
F=13N
Therefore, the student must exert 13N of force.