Download Phy 1053 Exam #1 Answer 5 problems out of 8

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
displacement vector
has a magnitude of 2.43 km and points due north. A second
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 3.0 m/s. A ballast bag is released
from rest relative to the balloon when it is 9.5 m above the ground. How much time
elapses before the ballast bag hits the ground.
6- An airplane moving horizontally with a constant velocity of +115 m/s at an altitude of
1050 m. 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
Average velocity
Instantaneous velocity
Average acceleration
y Component
Instantaneous acceleration
Newton’s
second law
Newton’s
second law
Newton’s law
of universal
gravitation