Phy 1053 Exam #1
Answer 5 problems out of 8
1-A highway is to be built between two towns, one of which lies 35.0 km south and 72.0 km west of the other. What is the shortest length of highway that can be built between the two towns, and at what angle would this highway be directed with respect to due west?
2-One displacement vector has a magnitude of 2.43 km and points due north. A second displacement vector has a magnitude of 7.74 km and also points due north. (a) Find the magnitude and direction of . (b) Find the magnitude and direction of .
3-In a historical movie, two knights on horseback start from rest 88.0 m apart and ride directly toward each other to do battle. Sir George’s acceleration has a magnitude of 0.300 m/s2, while Sir Alfred’s has a magnitude of 0.200 m/s2. Relative to Sir George’s starting point, where do the knights collide?
4-On a sunny day, a tall building casts a shadow that is 67.2 m long. The angle between the sun’s rays and the ground is , as Figure 1 shows. Determine the height of the building.
5-A hot-air balloon is rising straight up with a speed of 3.0m/s. A ballast bag is released from rest relative to the balloon when it is 9.5m above the ground. How much time elapses before the ballast bag hits the ground.
6-An airplane moving horizontally with a constant velocity of +115m/s at an altitude of 1050m. The directions to the right and upward have been chosen as the positive directions. The plane releases a “care package” that falls to the ground along a curved trajectory. Ignoring air resistance, determine the time required for the package to hit the ground.
7-A man is stranded on a raft (mass of man and raft=1300 kg). By paddling, he causes an average force of 17 N to be applied to the raft in a direction due east (the +x direction). The wind also exerts a force on the raft. This force has a magnitude of 15 N and points 67° north of east. Ignoring any resistance from the water, find the x and y components of the raft’s acceleration.
8-Suppose that A mass of A spacecraft is mS=11 000 kg and that the mass of the astronaut is mA=92 kg. In addition, assume that the astronaut exerts a force of on the spacecraft. Find the accelerations of the spacecraft and the astronaut.
Phy 1053 Exam #1 Formula sheet
Average speed /Average velocity /
Instantaneous velocity /
Average acceleration /
Instantaneous acceleration /
Equations of kinematics /
Motion in 2D
x Component / y ComponentAverage velocity /
Instantaneous velocity /
Average acceleration /
Instantaneous acceleration /
Newton’s second law /
Newton’s second law /
Newton’s law of universal gravitation /