Exercise 3 - Texas A&M University

1 9/26/2016 MasteringPhysics: Print View with answers Ch 3 Supplemental Questions [ Edit ]. Overview Summary View Diagnostics View Print View with answers Ch 3 Supplemental Questions Due: 7:00pm on Wednesday, September 28, 2016. To understand how points are awarded, read the Grading Policy for this assignment. Exercise Description: On level ground a shell is fired with an initial velocity of v0 at phi above the horizontal and feels no appreciable air resistance. (a) Find the horizontal and vertical components of the shell's initial velocity. (b) How long does On level ground a shell is fired with an initial velocity of m/s at above the horizontal and feels no appreciable air resistance.

2 Part A. Find the horizontal and vertical components of the shell's initial velocity. Enter your answers numerically separated by a comma. ANSWER: v0h v0v , = , = , m/s Part B. How long does it take the shell to reach its highest point? Express your answer using three significant figures. ANSWER: t = = Also accepted: = , = Part C. Find its maximum height above the ground. Express your answer using three significant figures. ANSWER: 1/11. 9/26/2016 MasteringPhysics: Print View with answers hmax = = Also accepted: = , = Part D. How far from its firing point does the shell land? Express your answer using three significant figures. ANSWER: l = = 105.

3 Also accepted: = 105 , = 105. Part E. At its highest point, find the horizontal and vertical components of its acceleration. Enter your answers numerically separated by a comma. ANSWER: ah , av = 0, m/s 2. Part F. At its highest point, find the horizontal and vertical components of its velocity. Enter your answers numerically separated by a comma. ANSWER: vh , vv = , = , 0 m/s Exercise Description: In a carnival booth, you win a stuffed giraffe if you toss a quarter into a small dish. The dish is on a shelf above the point where the quarter leaves your hand and is a horizontal distance of m from this point (the figure ). If you toss the coin.

4 In a carnival booth, you win a stuffed giraffe if you toss a quarter into a small dish. The dish is on a shelf above the point where the quarter leaves your hand and is a horizontal distance of m from this point (the figure ). If you toss the coin with a velocity of m/s at an angle of 60 above the horizontal, the . 2/11. 9/26/2016 MasteringPhysics: Print View with answers a velocity of m/s at an angle of 60 above the horizontal, the . coin lands in the dish. You can ignore air resistance. Part A. What is the height of the shelf above the point where the quarter leaves your hand? Express your answer using two significant figures. ANSWER: H = m Part B.

5 What is the vertical component of the velocity of the quarter just before it lands in the dish? Express your answer using two significant figures. ANSWER: vy = m/s Exercise Description: A jet plane comes in for a downward dive as shown in below. The bottom part of the path is a quarter circle with a radius of curvature of 280 m . According to medical tests, pilots lose consciousness when they pull out of a dive at an A jet plane comes in for a downward dive as shown in below. The bottom part of the path is a quarter circle with a radius of curvature of 280 m . According to medical tests, pilots lose consciousness when they pull out of a dive at an upward acceleration greater than.

6 3/11. 9/26/2016 MasteringPhysics: Print View with answers Part A. At what speed (in m/s) will the pilot black out for this dive? ANSWER: v = 120 m/s Also accepted: 123, 123, 120. Part B. At what speed (in mph) will the pilot black out for this dive? ANSWER: v = 270 mph Also accepted: 275, 275, 270. Exercise Description: A model of a helicopter rotor has four blades, each of length L from the central shaft to the blade tip. The model is rotated in a wind tunnel at a rotational speed of f. (a) What is the linear speed of the blade tip? (b) What is the A model of a helicopter rotor has four blades, each of length m from the central shaft to the blade tip.

7 The model is rotated in a wind tunnel at a rotational speed of 530 rev/min . Part A. What is the linear speed of the blade tip? ANSWER: 4/11. 9/26/2016 MasteringPhysics: Print View with answers v = = 172 m/s Part B. What is the radial acceleration of the blade tip expressed as a multiple of the acceleration of gravity, g? ANSWER: a = = 974 g Problem Description: In fighting forest fires, airplanes work in support of ground crews by dropping water on the fires. A pilot is practicing by dropping a canister of red dye, hoping to hit a target on the ground below. (a) If the plane is flying in a horizontal In fighting forest fires, airplanes work in support of ground crews by dropping water on the fires.

8 A pilot is practicing by dropping a canister of red dye, hoping to hit a target on the ground below. Part A. If the plane is flying in a horizontal path at an altitude of m above the ground and with a speed of m/s , at what horizontal distance from the target should the pilot release the canister? Ignore air resistance. Take free fall acceleration to be g. ANSWER: x = = 294 m Problem Description: A kg boulder is rolling horizontally at the top of a vertical cliff that is 20 m above the surface of a lake, as shown in the figure . The top of the vertical face of a dam is located 100 m from the foot of the cliff, with the top of the A kg boulder is rolling horizontally at the top of a vertical cliff that is 20 m above the surface of a lake, as shown in the figure.

9 The top of the vertical face of a dam is located 100 m from the foot of the cliff, with the top of the dam level with the surface of the water in the lake. A level plain is 25 m below the top of the dam. 5/11. 9/26/2016 MasteringPhysics: Print View with answers Part A. What must be the minimum speed of the rock just as it leaves the cliff so it will travel to the plain without striking the dam? Express your answer using two significant figures. ANSWER: v0x = 49 m/s Part B. How far from the foot of the dam does the rock hit the plain? Express your answer using two significant figures. ANSWER: L = 50 m Problem Description: Two soccer players, Mia and Alice, are running as Alice passes the ball to Mia.

10 Mia is running due north with a speed of v_M. The velocity of the ball relative to Mia is v_b in a direction degree(s) east of south. (a) What is the magnitude Two soccer players, Mia and Alice, are running as Alice passes the ball to Mia. Mia is running due north with a speed of m/s . The velocity of the ball relative to Mia is m/s in a direction east of south.. Part A. What is the magnitude of the velocity of the ball relative to the ground? Express your answer to three significant figures and include the appropriate units. ANSWER: 6/11. 9/26/2016 MasteringPhysics: Print View with answers v = = Part B. What is the direction of the velocity of the ball relative to the ground?