A brick is thrown from a wall that is 19.2 m above the ground and hits the ground 5.00 s later. What was the initial velocity of
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Answer: Work Done would remain same.
Let us assume that the velocity is constant while taking the load up the inclined plane. Then, the kinetic energy would remain the same. This is because kinetic energy is dependent on velocity . If that is constant, the kinetic energy would remain same. The potential energy is dependent on the height
. If the height is changed, then potential energy varies. In the question, it is mentioned that without changing the height, the length of the inclined plane is changed. Therefore, the potential energy would be same as before.
We know, work done is equal to potential energy plus kinetic energy. Since there is no change in any of these, the required work done would not change.
By using first and third equation of motion, the number of revolutions the tire makes during this motion is 43 rev.
ANGULAR MOTION
Since the car accelerate from rest, initial velocity will be zero.
Given that a car accelerates uniformly from rest and reaches a speed of 24.3 m/s in 9.1 s. The following are the given parameters
- Initial velocity U = 0
- Final velocity V = 24.3 m/s
- Time t = 9.1 s
If the diameter of a tire is 80.2 cm, to find the number of revolutions the tire makes during this motion, we must first calculate the distance travelled by the car by using first and third equation of motion of the car.
First equation
V = U + at
Substitute all necessary parameters into the equation.
24.3 = 0 + 9.1a
a = 24.3/9.1
a = 2.67 m/
Third Equation of motion
Substitute all the necessary parameters
= 0 + 2 x 2.67 x S
590.49 = 5.34S
S = 590.49 / 5.34
S = 110.58 m.
Given that the diameter of a tire is 80.2 cm,
the radius (r) will be 80.2/2 = 40.1 cm
convert it to meter
r = 40.1/100 = 0.401 m
The Circumference of the tire = 2r
Circumference = 2 x 3.143 x 0.401
Circumference = 2.52 m
Assuming no slipping, number of revolutions = 110.58/2.52
Number of revolutions = 43.89 rev.
Number of revolutions = 43 rev.
Therefore, the number of revolutions the tire makes during this motion is 43 rev.
Learn more about circular motion here: brainly.com/question/6860269