Physics, 03.08.2019 03:30, mmaglaya1

Arecord of travel along a straight path is as follows: 1. start from rest with constant acceleration of 2.65 m/s2 for 17.0 s. 2. maintain a constant velocity for the next 1.60 min. 3. apply a constant negative acceleration of −9.39 m/s2 for 4.80 s. (a) what was the total displacement for the trip? b) what were the average speeds for legs 1, 2, and 3 of the trip, as well as for the complete trip

Answers: 1

Show answers

Answers

Hello

Let's solve the problem in the three different steps

1) Uniformly accelerated motion, with acceleration a_1 = 2.65~m/s^2

and for a total time of t_1=17~s

. The body is initially at rest, so the distance covered is given by
$S= \frac{1}{2}a_1t_1^2=382.9~m$
Calling v_f

and

the final and initial velocity, and since the v_i=0~m/s

because the body starts from rest, we can use
$a= \frac{v_f-v_i}{t}$
to find the final velocity after this first leg:
$v_{f}=v_i+a_1t_1=45~m/s$
And the average velocity in this first leg is
$v_1= \frac{v_f+v_i}{2}=22.5~m/s$

2) Uniform motion. The velocity is constant and it is equal to the final velocity of the first leg: v_2=45~m/s

. This is also the average velocity of the second leg.
The total time of this second leg is t_2=1.60~min = 96~s

. The distance covered is given by
$S_2=v_2t_2=45~m/s \cdot 96~s=4320~m$

3) Uniformly decelerated motion, with constant deceleration of a_3=-9.39~m/s^2

and for a total time of t_3=4.8~s

. Here, the initial velocity of the body is the final velocity of the previous leg, i.e. v_i=45~m/s

. Therefore, the distance covered in this leg is given by
$S_3=v_i t_3 + \frac{1}{2} a_3 t^2 =107.8~m$
The final velocity in this leg is given by
$v_f=v_i+at=45~m/s-9.39~m/s^2 \cdot 4.8~s = -0.07~m/s$
The negative sign means that after decelerating, the body has started to go in the opposite direction. Similarly to step 1, the average velocity in this leg is given by
$v_3 = \frac{1}{2}(v_f+v_i)= \frac{1}{2}(-0.07~m/s+45~m/s)= 22.5~m/s$

4) Finally, the total distance covered in the motion is
S=S_1+S_2+S_3=382.9~m+4320~m+107.8~m=4810.7~m

S=S_1+S_2+S_3=382.9~m+4320~m+107.8~m=4810.7~m

To find the average velocity, we must "weigh" the average velocity of each leg for the correspondent time of that leg:
$v_{ave}= \frac{v_1t_1+v_2t_2+v_3t_3}{t_1+t_2+t_3}=40.8~m/s$

answered: Guest

m₁v₁ + m₂v₂ = (m₁ + m₂)vmomentum is conserved.the left-hand side of the equation represents the momentum in the system before the collision.the right-hand side represents the momentum in the system after the collisionm₁ and v₁ represents the mass and the velocity of the physics blockm₂ and v₂ represents the mass and velocity of the ball of puttyv represents the final velocity of the combined mass.the question states the two masses stick together. they combined mass has its own velocity with the body mass the sum of the two objects' massestheir combined momentum is (m₁ + m₂)vto find the magitude of (m₁ + m₂)v, we need to add the vectors on the left-hand side of the equation: m₁v₁ + m₂v₂.note the diagram. i have positioned the vectors in accordance with their directions.the magnitude of the resultant can be calculated using the pythagorean theorem since this is a right triangle situation (north and west are perpendicular)|(m₁ + m₂)v| = √[ (m₁v₁)² + (m₂v₂)² ]|(m₁ + m₂)v| = √[ (1.5kg·8.0m/s)² + (0.40kg·20m/s)² ]|(m₁ + m₂)v| = 14.4 kg m/sfor two significant figures (assuming that 20m/s is two), this rounds to 14 kg m/s

answered: Guest

The inference is supported by evidence in the graph is this is an exothermic reaction where the total release of energy equals a + c.

Other questions on the subject: Physics

Physics, 22.06.2019 07:30, Trup1822

The slope of a velocity time graph over any interval of time gives the during that interval

Answers: 1

continue

Physics, 22.06.2019 09:40, dakshshberry

Asatellite component is in the shape of a cube with 10cm edges, has an evenly distributed mass of 2 kg and one bolt hole at each of four corners. if the maximum predicted random vibration environment is 10 grms, what bolt size would be a good choice for restraint? what other factors might drive bolt size besides force/stress?

Answers: 2

continue

Physics, 22.06.2019 11:30, 21ghostrider21

Which of these questions might a character ask if the conflict is man versus self? a. which path should i take to better myself? b. which boulder will be too heavy for me to carry? c. which friend is going to ditch me today? d. all of the above

Answers: 1

continue

Physics, 22.06.2019 13:00, mandilynn22

Nacidified solution was electrolyzed using copper electrodes. a constant current of 1.18 a caused the anode to lose 0.584 g after 1.52 ✕ 103 s. given that the charge of an electron is 1.6022 ✕ 10−19 c, calculate avogadro's number. assume that copper is oxidized to cu2+ ions.

Answers: 1

continue

Do you know the correct answer?

Arecord of travel along a straight path is as follows: 1. start from rest with constant acceleratio...