ASSIGNMENT 6 keys
1.Knight 6.047. [370373]Show Details
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A rocket-powered hockey puck has a thrust of 1.5 N and a total mass of 1.0 kg. It is released from rest on a frictionless table, 2.5 m from the edge of a 2.0 m drop. The front of the rocket is pointed directly toward the edge. How far does the puck land from the base of the table?
[2.06] m
2.Knight 6.062. [455026]Show Details
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Susan, driving north at 45 mph, and Shawn, driving east at 45 mph, are approaching an intersection. What is Shawn's speed relative to Susan's reference frame?
[63.6] mph
3.Knight 6.043. [370374]Show Details
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Sam (60 kg) takes off (from rest) up a 50 m high, 10° frictionless slope on his jet-powered skis. The skis have a thrust of 240 N. He keeps his skis tilted at 10° after becoming airborne, as shown in Figure P6.43. How far does Sam land from the base of the cliff?
[179] m
Figure P6.43
4.Knight 6.002. [370377]Show Details
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A sailboat is traveling east at 5.5 m/s. A sudden gust of wind gives the boat an acceleration = (0.90 m/s2, 40° north of east). What are the boat's speed and direction 6.0 s later when the gust subsides?
[10.2] m/s [19.8]° north of east
5.Knight 6.004. [455024]Show Details
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A rocket-powered hockey puck moves on a horizontal frictionless table. Figure Ex6.4 shows graphs of vx and vy, the x- and y-components of the puck's velocity.
Figure Ex6.4
(a) In which direction is the puck moving at t = 3 s?
[51.3]° above the x-axis
(b) How far from the origin is the puck at t = 3 s?
[96.9] cm
6.Knight 6.005. [370370]Show Details
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As a science fair project, you want to launch an 800 g model rocket straight up and hit a horizontally moving target as it passes 25 m above the launch point. The rocket engine provides a constant thrust of 15.0 N. The target is approaching at a speed of 15 m/s. At what horizontal distance between the target and the rocket should you launch?
[35.5] m
7.Knight 6.010. [455040]Show Details
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2.5
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2.5
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2.5
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10
Two spheres are launched horizontally from a 1.0 m high table. Sphere A has a mass of 1.4 kg and is launched with an initial speed of 4.5 m/s. Sphere B has a mass of 0.5 kg and is launched with an initial speed of 2.0 m/s.
(a) Find the times for each sphere to hit the floor.
tA = [0.452] s
tB = [0.452] s
(b) Find the distances that each travels from the edge of the table.
xA = [2.03] m
xB = [0.904] m
8.Knight 6.011. [370376]Show Details
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A rifle is aimed horizontally at a target 54 m away. The bullet hits the target 2.2 cm below the aim point.
(a) What was the bullet's flight time?
[0.067] s
(b) What was the bullet's speed as it left the barrel?
[806] m/s
9.Knight 6.013. [455044]Show Details
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A boat takes 4 hours to travel 30 km down a river, then 7.5 hours to return. How fast is the river flowing?
[1.75] km/hr
10.Knight 6.012. [484200]Show Details
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A ball thrown horizontally at 20 m/s travels a horizontal distance of 50 m before hitting the ground. From what height was the ball thrown?
[30.6] m