Q.3 - Consider a block of mass m = 2 kg on an inclined surface as shown in the figure below. The x- component of its weight is (Take g = 10 m/s²) : e-40 mg_x = -20 sin(40) O mg_x = +20 sin(40) mg_x = -20 cos(40) O mg_x = +20 cos(40)

Q.3 - Consider a block of mass m = 2 kg on an inclined surface as shown in the figure below. The x- component of its weight is (Take g = 10 m/s²) : e-40 mg_x = -20 sin(40) O mg_x = +20 sin(40) mg_x = -20 cos(40) O mg_x = +20 cos(40)

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter4: The Laws Of Motion

Section: Chapter Questions

Problem 11P

See similar textbooks

Similar questions

The distinction between mass and weight was discovered after Jean Richer transported pendulum clocks from Paris, France, to Cayenne, French Guiana, in 1671. He found that they quite systematically ran slower in (Cayenne than in Paris. The effect was reversed when the clocks returned to Paris. How much weight would a 90.0 kg person lose in traveling from Paris, where g = 9.809 5 m/s2, to Cayenne, where g = 9.780 8 m/s2? (We will consider how the free-fall acceleration influences the period of a pendulum in Section 15.5.)
An astronaut in her space suit has a total mass of 87.0 kg, including suit and oxygen tank. Her tether line loses its attachment to her spacecraft while shes on a spacewalk. Initially at rest with respect to her spacecraft, she throws her 12.0-kg oxygen tank away from her spacecraft with a speed of 8.00 m/s to propel herself back toward it (Fig. P6.29). (a) Determine the maximum distance she can be from the craft and still return within 2.00 min (the amount of time the air in her helmet remains breathable), (b) Explain in terms of Newtons laws of motion why this strategy works. Figure P6.29
In Chapter 5 we will define the center of mass of an object The center of mass moves with constant acceleration when constant forces act on the object A gymnast jumps straight up, with her center of mass moving at 2.80 m/s as she leaves the ground. How high above this point is her center of mass (a) 0.100 s, (b) 0.200 s, (c) 0.300 s, and (d) 0.500 s thereafter?
The third graders are on one side of a schoolyard, and the fourth graders are on the other. They are throwing snowballs at each other. Between them, snowballs of various masses are moving with different velocities as shown in Figure OQ5.3. Rank the snowballs (a) through (e) according to the magnitude of the total force exerted on each one. Ignore air resistance. If two snowballs rank together, make that fact clear.
Review. A rifle bullet with a mass of 12.0 g traveling toward the right at 260 m/s strikes a large hag of sand and penetrates it to a depth of 23.0 cm. Determine the magnitude and direction of the friction force (assumed constant) that acts on the bullet.
Professional Application A 75.0-kg person is riding in a car moving at 20.0 m/s when the car runs into a bridge abutment. (a) Calculate the average force on the person if he is stopped by a padded dashboard that compresses an average of 1.00 cm. (b) Calculate the average force on the person if he is stopped by an air bag that compresses an average of 15.0 cm.
An air bag inflates when a collision occurs, protecting a passenger (the dummy in Figure CQ6.12) from serious injury. Why does the air bag soften the blow? Discuss the physics involved in this dramatic photograph.
Physics Review A soap bubble hovers motionlessly in the air. If the soap bubbles mass, including the air inside it, is 2.00 104 kg determine the magnitude of the upward force acting on it. (See Section 4.5.)
An airplane of mass 1.50 104 kg is in level flight, initially moving at 60.0 m/s. The resistive force exerted by air on the airplane has a magnitude of 4.0 104 N. By Newtons third law, if the engines exert a force on the exhaust gases to expel them out of the back of the engine, the exhaust gases exert a force on the engines in the direction of the airplanes travel. This force is called thrust, and the value of the thrust in this situation is 7.50 104 N. (a) Is the work done by the exhaust gases on the airplane during some time interval equal to the change in the airplanes kinetic energy? Explain. (b) Find the speed of the airplane after it has traveled 5.0 102 m.
An amusement park ride consists of a large vertical cylinder that spins about its axis fast enough that any person inside is held up against the wall when the floor drops away (Fig. P5.60). The coefficient of static friction between person and wall is s, and the radius of the cylinder is R. (a) Show that the maximum period of revolution necessary to keep the person from falling is T=(42Rs/g)1/2. (b) If the rate of revolution of the cylinder is made to be somewhat larger, what happens to the magnitude of each one of the forces acting on the person? What happens in the motion of the person? (c) If the rate of revolution of the cylinder is instead made to be somewhat smaller, what happens to the magnitude of each one of the forces acting on the person? What happens in the motion of the person?
The gravitational force on the basketball in Figure 4.6 is ignored. When gravity is taken into account, what is the direction of the net external force on the basketball—above horizontal, below horizontal, or still horizontal? Figure 4.6 The same force exerted on systems of different masses produces different accelerations. (a) A basketball player pushes on a basketball to make a pass. (The effect of gravity on the ball is ignored.) (b) The same player exerts an identical force on a stalled SUV and produces a far smaller acceleration (even if friction is negligible). (c) The free-body diagrams are identical, permitting direct comparison of the two situations. A series of patterns for the free-body diagram will emerge as you do more problems.
A basketball star covers 2.80 m horizontally in a jump to dunk the ball (Fig. P4.12a). His motion through space can be modeled precisely as that of a particle at his center of mass, which we will define in Chapter 9. His center of mass is at elevation 1.02 m when he leaves the floor. It reaches a maximum height of 1.85 m above the floor and is at elevation 0.900 m when he touches down again. Determine (a) his time of flight (his hang time), (b) his horizontal and (c) vertical velocity components at the instant of takeoff, and (d) his takeoff angle. (e) For comparison, determine the hang time of a whitetail deer making a jump (Fig. P4.12b) with center of mass elevations yi = 1.20 m, ymax = 2.50 m, and yf = 0.700 m. Figure P4.12