5. A car advertisement states that a certain car can accelerate from rest to 70 m/s in 7 seconds. Find the car's average acceleration.
O-0.10 m/s^2
10 m/s^2
-10 m/s^2
O 0.10 m/s^2

The car's average acceleration is .

Explanation:

Constant Acceleration Motion

It's a type of motion in which the velocity of an object changes by an equal amount in every equal period of time.

Being vo the initial speed, a the constant acceleration, vf the final speed, and t the time, the following relation applies:

If we need to find the acceleration, we solve the above equation for a:

The car accelerates from rest (vo=0) to vf=70 m/s in t=7 seconds. Substitute the values into the formula:

The car's average acceleration is .

Note: The choices are not very clear, but the second choice seems to be the correct answer.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2