Average Speed, and Acceleration Problems.

[asimon2008]

I'm been busy doing my other homework and I need someone to help me with this.

 

I have 4 problems, please help me. I need these answers by 7:00 a.m. please.

 

48. A train on a staright, level track has an initial speed of 35.0km/h. A uniform acceleration of 1.50 m/s is applied while the train travels 200 m. (a) What is the speed of the train at the end of this distance? (:coffee_n_pc: How long did it take for the train to travel the 200 m?

 

52. A car initially traveling to the right at a steady speed of 25 m/s for 5.0 s applies its brakes and slows at a constant rate of 5 m/s^2 for 3.0 s. It then continues traveling to the right at a steady but slower speed with no additional braking for another 6.0 s. (a) To help with the calculations, make a sketch of the car's velocity versus time, being sure to show all three times intervals. ( What is its velocity after the 3.0s of braking? © What was its displacement during the total 14.0 s of its motion? (d) What was its average speed for the 14.0 s?

 

72. The speed limit in a school zone is 40 km/h (about 25 mi/h). A driver traveling at this speed sees a child run onto the road 13 m ahead of his car. He applies the brakes, and the car decelerates at a uniform rate of 8.0 m/s^2. If the driver's reaction time is 0.25 s, will the car stop before hitting the child?

 

98. The ceiling of a classroom is 3.75 m above the floor. A student tosses an apple vertically upward, releasing it 0.50 m above the floor. What is the maximum initial speed that can be given to the apple if it is not to touch the ceiling?

[freeztar]

I'm been busy doing my other homework and I need someone to help me with this.

 

I have 4 problems, please help me. I need these answers by 7:00 a.m. please.

While we are glad to *help* with homework problems, we are not here to *answer* them for you.

48. A train on a staright, level track has an initial speed of 35.0km/h. A uniform acceleration of 1.50 m/s is applied while the train travels 200 m. (a) What is the speed of the train at the end of this distance? (:coffee_n_pc: How long did it take for the train to travel the 200 m?

These questions are asking you to convert between units of measurement. You must then apply the formula for velocity.

52. A car initially traveling to the right at a steady speed of 25 m/s for 5.0 s applies its brakes and slows at a constant rate of 5 m/s^2 for 3.0 s. It then continues traveling to the right at a steady but slower speed with no additional braking for another 6.0 s. (a) To help with the calculations, make a sketch of the car's velocity versus time, being sure to show all three times intervals. ( What is its velocity after the 3.0s of braking? © What was its displacement during the total 14.0 s of its motion? (d) What was its average speed for the 14.0 s?

If you can show your sketch, we can try to help you from there.

 

72. The speed limit in a school zone is 40 km/h (about 25 mi/h). A driver traveling at this speed sees a child run onto the road 13 m ahead of his car. He applies the brakes, and the car decelerates at a uniform rate of 8.0 m/s^2. If the driver's reaction time is 0.25 s, will the car stop before hitting the child?

 

98. The ceiling of a classroom is 3.75 m above the floor. A student tosses an apple vertically upward, releasing it 0.50 m above the floor. What is the maximum initial speed that can be given to the apple if it is not to touch the ceiling?

 

In general, please provide the work that you have so far and then we will help you from there. :)

[asimon2008]

thanks anyways.