Question

A right triangle has hypotenuse 13 cm and one side 7 cm. Find the length of the other side, and the sine, cosine and tangent of each of the other two angles. A man running 4 m/s is passed by a car at 20 m/s, both heading East. What is the velocity of the man relative to the car? How far apart are the 20 seconds after the car passes the man? A ball is thrown vertically upwards from the top of a 25 high building and just missed the edge of the roof 4 seconds later on its way down. At the initial velocity was the ball what initial ground, thrown? What is its velocity as it passes the roof? How long does it take to hit the ground with what velocity does it do so? An 80 kg man stands on a weight reading (in kilograms) scale in the elevator moving downwards. What does the scale read when the elevator moves at a constant velocity of 2m/s? What does the scale read when the elevator decelerates at 2 m/s^2? Two forces F_1 = 40 N, East and F_2 = 30 N. South, act on an object of mass 5 kg. What is it's acceleration? What are the weight and mass of the object on planet X, where g_x = 12 m/s^2? Two runners collide head on and end up at rest. The first runner has a mass of 100 kg and the initial velocity of 8 m/s. The second runner has mass 80 kg. What is the momentum change of the first runner? What was the initial velocity of the second runner? What is the torque about the shoulder if the arm is an abducted position at 60 degrees from the body in the frontal plane while holding a 10 kg dumbbell? Assume that the mass of the arm is 6 kg, its center of mass is located 38 cm from the shoulder joint center, and the arm's total length is 80 cm. A simple pendulum has period 2 seconds on Earth. What is its period on the Moon. where g_M = 1.6 m/s^2? What would its length have to be in order for its period on the moon to be 2 seconds? A block of mass M oscillates horizontally attached to an ideal spring with the spring constant k. Using the laws of motion, derive the formula for the period of oscillation of the system. A wave travels along the cable at 20 m/s. If its frequency is 2 Hz, what is its wavelength? Assume the cable has a mass 100 kg and length 20m. What is its tension? A pipe is 4 m long. Find the frequencies of the first three harmonics at 10degreeF if: The pipe is open on both ends. The pipe is open at one end and closed at the other. A block of wood has density 600 kg/m^3. mass 3 kg, length 50cm, and width 20cm. What is its thickness? Calculate how much energy it takes to raise the temperature of 500g of water from 10degreeC to 50degreeC (c_water = 4186 1/kg middot K)

Answer 1

1.

From pythagoras theorem

L²=13²-7²

L=10.95 cm

angles

sino=7/13=0.538

coso=10.95/13=0.842

tano=7/10.95=0.639