Physics, Kinematics

posted by .

You drive with a constant speed of 15.1 m/s for 23.4 s. You then accelerate for 28.7 s to a speed of 25.8 m/s. You then slow to a stop in 37.1 s. How far have you traveled?

I've tried dividing this into 3 parts.
1st- constant speed
15.1m/s*23.4s=353.34 m

2nd-accelerating
I solved for acceleration, v=v0+at, a=0.0836 m/s^2, then plugged into x=x0+v0t+(1/2)at^2 where x=0+(23.4m/s)(28.7s)+(1/2)(.0836m/s^2)(28.7)^2=706.35

353.34+706.35=1059.35

I'm stuck after this. What do I do with the negative acceleration for the last part? I appreciate any guidance.

• Physics, Kinematics -

ok on first leg.
Second leg, accelerating;
distance= average velocity*time
= 1/2 (15.1+28.7)*25.8

third leg:
distance= avg velocity*time
= 1/2 (28.7+0)*37.1

• Physics, Kinematics -

That isn't correct. Any other thoughts on this problem?

• Physics, Kinematics -

Nevermind, you just accidentally switched the velocity and time. It's (1/2)(15.1+25.8)*(28.7) and (1/2)(25.8)*37.1. Thank you so much for your help! I can't believe I didn't see that before.

Similar Questions

1. Physics

A 747 jetliner lands and begins to slow to a stop as it moves along the runway. If its mass is 3.42×105 kg ,its speed is 29.5 m/s,and the net braking force is 4.3*10^5 N. What is its speed 8.33 s later?
2. Engineering Physics

A car and a train move together along straight, parallel paths with the same constant cruising speed v(initial). At t=0 the car driver notices a red light ahead and slows down with constant acceleration -a(initial). Just as the car …
3. physics

A 747 jetliner lands and begins to slow to a stop as it moves along the runway. If its mass is 3.50x^5 kg. Its speed is 27.0 m/s, and the net braking force is 4.30x10^5 N. (a)what is its speed 7.50 s later?
4. physics

A 747 jetliner lands and begins to slow to a stop as it moves along the runway. The mass is 3.1 105 kg, its speed is 25.5 m/s, and the net braking force is 4.24 105 N.(a) What is its speed 7.45 s later?
5. physics

A 747 jetliner lands and begins to slow to a stop as it moves along the runway. If its mass is 3.5 x 10 exponent 5 kg, its speed is 27.0 m/s and the net braking force is 4.30 x 10 exponent 5 N, (A) what id its speed 7.50 s later?
6. Physics

. The cheetah is the fastest running animal in the world. Cheetahs can accelerate to a speed of 20 m/s in 2.5 an can continue to accelerate to reach a stop speed of 29 m/s. Assume the acceleration is constant until the stop speed is …
7. Physics

A 747 jetliner lands and begins to slow to a stop as it moves along the runway. If its mass is 3.50 x 105 kg, its speed is 27.0 m/s, and the net braking force is 4.73 x 105 N. (a) What is its speed 7.50 s later?
8. Physics

Two cars start from rest at a red stop light. When the light turns green, both cars accelerate forward. The blue car accelerates uniformly at a rate of 5 m/s2 for 4.2 seconds. It then continues at a constant speed for 11.1 seconds, …
9. physics

You are driving your car along a country road at a speed of 21.5 m/s. As you come over the crest of a hill, you notice a farm tractor 35.7 m ahead of you on the road, moving in the same direction as you at a speed of 10.0 m/s. You …
10. physics 101

You drive your car at a speed 40km/h for 1 hour, then slow down to 30km/h for the next 20km. How far did you drive, and what was your average speed?

More Similar Questions

Post a New Question