An object's acceleration is given by a(t)=a(t)=60t m/s260t m/s2 . if it begins at rest, how far has it gone after 10 seconds?

The object's acceleration is given by the expression: a(t) = 60t m/s^2. The distance it traveled after 10 seconds after starting from rest can be obtained by integrating the expression, a(t), twice in order to get the expression for the distance as a function of time. 

The first integral of a(t) is the velocity, v(t), of the object which is then equal to: v(t) = 30t^2. The integral of v(t) is then distance, d(t), of the object which is then equal to: d(t) = 10t^3. With the distance equation available, we simply plug in t = 10 seconds into the equation. It is then determined that the object has traveled 10,000 m or 10 km after 10 seconds starting from rest.    

Answer(b) both involve the use of levers;

We can infer that star y is closer but other factors must be considered include the heat of the star, the mass, and the brightness of the star. even though star x seems dimmer it may just be less bright or contains less heat.