The infield of a baseball field is a diamond that measures 90 feet on each side. A runner runs from first base to second base at the rate of 25 ft/sec. How fast is the runner moving away from home plate when he is 30 feet from first base?

If is the distance the runner travels between first and second base, then the distance between him and home plate satisfies

(where the 90 here refers to the distance between first base and home)

Differentiating both sides with respect to time gives

The runner's speed is . When he is away from first base, he is

away from home plate. So he is moving away from home plate at a rate of

there will be 35 boys in each team. : )

answer

a,b, and d

explanation

a reflection angle is more than

but less than;

an angle that measures

is a reflex angle.(true)

an angle that measures less than

is acute.(true)

provided we are considering angles greater or equal to zero.

an acute angle lies in the range.

an obtuse angle is less than 180° but more than 90°

an angle that measures 300° is obtuse (false)

an angle that measures 65° is an acute angle.(true)