Classical Mechanics Answers

A ball is projected vertically upwards with velocity v if another ball in the same manner thrown (i.e. with v and vertically upwards ) after 'n' second n can be ant positive number
1) find time after wich ball will meet (if possible)
2) hieght from projection plane at which they will meet?

A train that weighs 1,000,000KG is moving at a stable speed of 20m/s with a force of friction that equals 20,000N.

Q: Find the power of the train's locomotive.

One strategy in a snowball fight is to throw a snowball at a high angle over level ground. While your opponent is watching the first one, a second sbowball is thrown at a low angle timed to arrive before or at the same time as the first one. Assume both snowballs are thrown with a speed 25.0 m/s. The first one is thrown at an angle of 70.0 degrees with respect to the horizontal.

A. At what angle should the second snowball be thrown to arrive at the same point as the first?
B. How many seconds later should the second snowball be thrown after the first to arrive at the same time?

he velocity of a parachutist as a function of time is given by v = vf + (v0 −vf )e
[−t/(2.5s)]
,
where t =0 corresponds to the instant the parachute is opened, v0 = 200 km/h is the veloc-
ity before opening of the parachute, and vf = 18 km/h is the final (terminal) velocity. What
acceleration does the parachutist experience just after opening the parachute?

A boat is sailing in the direction of N 16o W at a speed of 225.21 km/h in still air. The wind is blowing to the direction of S 41o W at a speed of 116.69 km/h. Find the principle angle of the resultant.

A radar station locates a sinking ship at range 16.5 km and bearing 136° clockwise from north. From the same station, a rescue plane is at horizontal range 19.6 km, 162° clockwise from north, with elevation 2.15 km.
(a) Write the displacement vector from plane to ship, letting î represent east, ĵ north, and k up.

(b) How far apart are the plane and ship?

As it passes over Grand Bahama Island, the eye of a hurricane is moving in a direction 58.0° north of west with a speed of 39.6 km/h. (Let î represent east and ĵ represent north.)
(a) What is the unit-vector expression for the velocity of the hurricane?
km/h î + km/h ĵ

It maintains this velocity for 3.20 h, at which time the course of the hurricane suddenly shifts due north, and its speed slows to a constant 22.4 km/h. This new velocity is maintained for 1.50 h.
(b) What is the unit-vector expression for the new velocity of the hurricane?
km/h î + km/h ĵ

(c) What is the unit-vector expression for the displacement of the hurricane during the first 3.20 h?
km î + km ĵ

(d) What is the unit-vector expression for the displacement of the hurricane during the latter 1.50 h?
km î + km ĵ

(e) How far from Grand Bahama is the eye 4.70 h after it passes over the island?
km

The figure below illustrates typical proportions of male (m) and female (f) anatomies. The displacements d with arrow1m and d with arrow1f from the soles of the feet to the navel have magnitudes of 108 cm and 86.0 cm, respectively. The displacements d with arrow2m and d with arrow2f from the navel to outstretched fingertips have magnitudes of 97 cm and 85.0, respectively. Find the vector sum of these displacements d with arrow3 = d with arrow1 + d with arrow2 for both people.
for the male
magnitude cm
direction ° above the +x axis (first quadrant)

for the female
magnitude cm
direction ° above the +x axis (first quadrant)

If vector A = (6.00 i hat -8.00 j) units, vector B = (-8.00 i hat + 3.00 j) units, and vector C = (27.0 i hat + 19.0 j) units, determine a and b such that a vector A + b vector B + vector C= 0.
a =
b =

Three displacement vectors of a croquet ball are shown in the figure, where |vector A| = 18.0 units, |vector B| = 30.0 units, and |vector C| = 20.0 units.

(a) Find the resultant in unit-vector notation.
R with arrow =

(b) Find the magnitude and direction of the resultant displacement.
units
° (from the +x axis)