1) a car accelerates uniformly from rest and reaches a speed of 19.8 m/s in 7 s. the diameter of a tire is 38.5 cm. find the number of revolutions the tire makes during this motion, assuming no slipping. answer in units of rev.

2) a wheel has a radius of 4.8 m. how far (path length) does a point on thecircumference travel if the wheel is rotatedthrough an angle of 54◦? answer in units of m.

3) how far (path length) does a point on thecircumference travel if the wheel is rotatedthrough an angle of 319 rad? answer in units of m

1) 57 revolutions.

2) 4.52 m

3) 1531.2 m

Explanation:

Question 1:

Given:

Initial velocity,

Final velocity,

Time,

Acceleration,

Now, displacement of the tire is given as:

Displacement of tire in 1 revolution is equal to its circumference.

Therefore, displacement in 1 revolution =

Now, number of revolutions is given as:

Therefore, the number of revolutions are 57.

Question 2:

Given:

Radius of the wheel is,

Angle of rotation is, °

Converting degree to radians, we get:

Now, path length is given as:

Therefore, the path length of a point on the wheel is 4.52 m

Question 3:

Radius of the wheel is,

Angle of rotation is, radians

Now, path length is given as:

Therefore, the path length of a point on the wheel is 1531.2 m.

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.