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Find the correct equivalence in scientific notation, if 172,000 gallons of gasoline are expressed in deciliters.
1galon = 37.85 dl
6.5x10^6 dl
This Is the capability of doing work given a position or condition
Potencial energy
A car wheel with a radius r=0.40 meters rotate at 16 rad/s. Find the distance travelled in 50 seconds.
320 m
Which of the following equations states that in an equilibrium system, where there is a rigid object, there is an equilibrium of all torques with respect to an anchor point?
Sumare t = 0
A highspeed train runs East at a speed of 320 miles per hour. Find the speed in meters per second
143.05 m/s
A school bus reduces its speed in a school zone from 120 km/h to 40 km/h in 8 s. Find its acceleration
a= -2.78 m/s2
Is the concepts that refers to the tendency to produce a change in the rotational motion
Torque
Find the momentum if a force applied to a wrench is 100 N.
Consider that the hand is pulling downwards 0.25 m
25 Nm
1. What is kinetic energy?
2. If an object is at rest, it will remain at rest unless an external force makes it move. Which of Newton’s laws describes this situation?
1.The capability of doing work with motion (mass and velocity)
2. First Newton's law
If you are interested in knowing what is the power consumed when lifting 1.6 m a 70 kg rock in 0.5 seconds, which formula would you use?
P= work/t
A crane lifts an 36 kg stone up to a 12 m height, then releases the stone.
Find the potential energy at the highest point and the total energy at the highest point.
U = 4233.6 J, K = 0, E = 4233.6J
Imagine that a goalkeeper kicks a ball at an initial velocity of 60 m/s in a 30° angle with respect to the horizontal.
Find the initial velocities in both “X” and “Y” axes
51.96 m/s =vx
30 m/s= vy
Find the height in meters that can be reached by a body if it is thrown upwards at an initial velocity of 80 ft/min
8.4179 x 10-3 m
An athlete starts from a standstill position with a constant acceleration during 19.9s until reaching a speed of 72.36 km/h
Find the acceleration
a=1.01 m/s2
1.What is the statement of the theorem of conservation of total mechanical energy?
2.Ricardo is 18 years old, his height is 1.80 m, and his mass is 70 kg; what is his weight?
1.In the absence of friction, the sum of both energies potential and kinetic is a constant.
2. 686.7 N
A 100 N force is applied to the handle of a lawnmower which displaces 20 meters. If the handle forms a 45° angle with respect to the floor, find the work performed by the applied force
1,414.12 Joules
1. This is the unit that establishes the angle among the arch and the radius of a circle.
2.What is the condition to obtain translational equilibrium?
1.Radian
2.There is no resultant force
Find the kinetic energy in a ball whose mass is 15 kg and travels at 40 ft/s
4459.34 Joules
KE= (24.384 m/s)^2 (0.5) (15kg)
If you let a marble roll at velocity of 15 m/s on a desk with a 1.2 m height, find the horizontal distance the marble will travel and fall simultaneously from the surface of the desk.
7.35 m
A player kicks the ball at a speed of 80 m/s, with a 60° angle above the grass. Find the time the ball takes to reach the maximum height
t= 7.06 s
1.A chopper whose mass is 1,600 kg elevates from the ground at a velocity of 12 m/s. Find the total energy of the chopper when the height is 60 m.
2.In a racing track a car runs 200 km in 60 minutes.
What should be done to find the speed of the car?
1. 1 056 960 Joules
2. Indirect measurement
If you release an object from the top of a building whose height is 600 m. Find the time that the object remains in the air just before it touches the floor.
11.07 s
Make the first free body diagram
A = 115.47 N, B = 57.73 N
Sumatoria de las fuerzas es igual a 0.
0 = A sinθ -100
A=100N/sin 60 = 115.47 N
115.47 Cos (60) = 57.73 N
Jorge rides a bike to school and follows this path: 10 km to the North, 8 km to the East, and 4 km to the Northeast.
Find the magnitude and direction of the resultant vector
16.77 km and 49.82º
Make the second body diagram
0= B sin 30 – A
0 = B Cos 30 – 400 N
400N/Cos 30 = B B= 461.88N
A= 461.88N Sin 30 = 231.2 N