Physics, 02.01.2020 00:31 bncm766

1-a car moves toward east 12km is represented as a and it turns towards south 16km is represented as b. what is the resultant vector of a-b
a-20 km south east
b-25 km south east
c-20km north east
d-25 km north east

2-a stone is thrown horizontally from the top of a tower of height 78.4 m. it reaches 40 m away from the foot of the tower. what is its initial velocity of projection?
h=1/2gt^2
x=vx^2
a=2.5 m/s
b=5 m/s
c=7.5 m/s
d=10 m/s

a storm is projected horizontally with a velocity of 16 m/s from the bridge at a height of 20 m from the river. how far away (x) parentheses from the bridge is the stone when it reaches the river
h= 1/2gt^2
x=vx^2
a= 36 m
b=32.32 m
c=4m
d=24.23 m

Answers: 3

Show answers

Answers

Answer from: smilequi9653

1. A-20 km south east

The car's displacement consists of two components into two different directions. Using a system of coordinates in which x represents the east direction and y represents the south direction, the two displacements are:

d_x = 12 km east

d_y = 16 km south

Since the two components are orthogonal to each other, we can find the resultant displacement by using Pythagorean's theorem:

$d=\sqrt{d_x^2+d_y^2}=\sqrt{(12 km)^2+(16 km)^2}=\sqrt{400}=20 km$

and the direction is between the two original directions, so south-east.

2. D. 10 m/s

First of all, we need to calculate the total time the stone took to hit the ground. Since the vertical distance covered is S = 78.4 m, and since the motion is an accelerated motion with constant acceleration g=9.8 m/s^2, we have

$S=\frac{1}{2}gt^2$

From which we find the total time of the fall, t:

$t=\sqrt{\frac{2S}{g}}=\sqrt{\frac{2(78.4 m)}{9.8 m/s^2}}=4 s$

Now we can consider the horizontal motion of the stone: we know that the stone travels for d = 40 m in a time of t = 4 s, therefore the horizontal velocity of the stone is

$v=\frac{d}{t}=\frac{40 m}{4 s}=10 m/s$

3. B=32.32 m

As in the previous problem, we have to calculate the total time it takes for the stone to reach the river first. Since the vertical distance covered is S = 20 m, we have

$t=\sqrt{\frac{2S}{g}}=\sqrt{\frac{2(20 m)}{9.8 m/s^2}}=2.0 s$

And since the stone is traveling horizontally at v = 16 m/s, the horizontal distance covered is

d=vt=(16 m/s)(2 s)=32 m

So, the closest answer is B.

Answer from: Quest

305.7

explanation:

density =m/v

density =917/3.00

density = 305.

approximately = 305.7

in four significant figures

Answer from: Quest

Distance covered, s = 8ft - 4ft = 4 ftinitial velocity, u = 34 ft/sthe acrobat is moving upwards and therefore, a = -g = -9.81 m/s^2 = 32.19 ft/s^2applying equation of motion; s = ut -1/2gt^2then,4 = 34t -1/2*32.19t^24 = 34t - 16.095t^2rearranging; -16.095t^2 + 34t - 4 = 0solving the quadratic equation; t = {-34 +/- sqrt [34^2 - 4(-16.)]}/2(-16.095) = 1.06 +/- 0.93 = 0.13 or 1.99the acrobat will take 0.13 seconds to be at 8 ft above the ground. additionally, once at the maximum height, the acrobat will move down and be at the same spot (that is height) after 1.99 seconds moving down.

Another question on Physics

Physics, 22.06.2019 06:10

Drag each tile to the correct box. tiles bra i sequence

Answers: 2

Answer

Physics, 22.06.2019 23:20

Consider each of the electric- and magnetic-field orientations given next. in each case, what is the direction of propagation of the wave? a)\vec ein the +xdirection,\vec bin the +ydirection. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction b)\vec ein the -y direction,\vec bin the +x choose+ x direction- x direction+ y direction- y direction+ z direction- z direction c)\vec ein the +z direction,\vec bin the -x direction. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction d)\vec ein the +y direction,\vec bin the -z direction. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction

Answers: 3

Answer

Physics, 23.06.2019 04:31

You have 80 g of 60oc water and 80 g or 10oc water. what is the final temperature when the two are mixed? explain.

Answers: 2

Answer

Physics, 23.06.2019 14:30

Multiple choice. choose the one alternative that best completes the statement or answers the question. 1) if the force on an object is in the negative direction, the work it does on the object must be 1) a) negative. b) positive. c) the work could be either positive or negative, depending on the direction the object moves. 2) a truck has four times the mass of a car and is moving with twice the speed of the car. if kt and kc refer to the kinetic energies of truck and car respectively, it is correct to say that 2) a) kt = 16kc . b) kt = 1 2 kc. c) kt = kc . d) kt = 2kc . e) kt = 4kc . 3) you and your friend, who weighs the same as you, want to go to the top of the eiffel tower. your friend takes the elevator straight up. you decide to walk up the spiral stairway, taking longer to do so. compare the gravitational

Answers: 1

Answer

You know the right answer?

1-a car moves toward east 12km is represented as a and it turns towards south 16km is represented as...

Questions