Mechanics | Relativity Answers

Two airplanes leave an airport at the same
time. The velocity of the first airplane is
710 m/h at a heading of 58◦
. The velocity of
the second is 630 m/h at a heading of 181◦
.
How far apart are they after 2.9 h?
Answer in units of m.

A speed skater moving across frictionless ice at 8.2 m/s hits a 5.7 m -wide patch of rough ice. She slows steadily, then continues on at 5.7 m/s

A train starts from rest at station A and is uniformly accelerated until it reaches speed of 108km/h. It then travel at this speed until the breaks are applied and the train is then uniformly retarded until it stops at station B. The magnitude of this retardation is twice the magnitude of the initial acceleration. The distance between the stations is 12km and the time taken for the journey is 10minutes. Find the 1. Time spent of each of the three stages of the journey. 2. Initial acceleration 3. Final retardation. Question 2 A stone 0.2kg is dropped over a cliff. Write down the force in Ns which acts on it and hence find its momentum after 3s. Take g=10m/s

A student throws a water balloon vertically downward from the top of a building. The balloon leaves the
thrower's hand with a speed of 6.00 m/s. Air resistance may be ignored, so the water balloon is in free
fall after it leaves the thrower's hand.
1.What is its speed after falling for 2.00 s?
2.How far does it fall in 2.00 s?

A mass of 200 gm is attached to a cord wound over a flywheel of mass 10 kg and
circumference 75 cm with an axle diameter 3 cm. A mark is made at a distance 2 cm in
radial direction from the edge of the flywheel. Calculate the angular velocity and linear
velocity of this mark when the time is 20 s after the mass is released from the rest.

Alex, a rescue pilot drops a survival kit while her plane is flying horizontally at an altitude of 1800.0 m with a forward velocity of 140.0 m/s. A group of lost Antarctica explorers is below on the ground.
How far in front of the explorers should Alex drop the supplies?

An elevator car has two equal masses attached to the ceiling as shown. (Assume
m = 3.10 kg.)
a. The elevator ascends with an acceleration of magnitude 1.00 m/s2. What are the tensions in the two strings? (Enter your answers in N.)
b. The maximum tension the strings can withstand is 75.0 N. What is the maximum acceleration of the elevator so that a string does not break? (Enter the magnitude in m/s2.)

Consider the Atwood machine shown in the figure, where
m1 = 2.00 kg
and
m2 = 5.90 kg.
The system starts at rest, then the sphere is given a quick push downward, giving it an initial speed of 2.95 m/s.
Assume the pulley and cord are massless, and the cord is inextensible. Neglect friction.
a. Through what distance (in m) will m1 descend?
b.What is the velocity (in m/s) of m1 after 1.80 s?
magnitude and direction

Assume the three blocks (m1 = 1.0 kg, m2 = 2.0 kg, and m3 = 4.8 kg) portrayed in the figure below move on a frictionless surface and a force F = 45 N acts as shown on the 4.8-kg block.
(a) Determine the acceleration given this system.

(b) Determine the tension in the cord connecting the 4.8-kg block and the 1.0-kg blocks.

(c) Determine the force exerted by the 1.0-kg block on the 2.0-kg block.

A 3.95-kg block starts from rest at the top of a 30.0° incline and slides a distance of 1.80 m down the incline in 1.90 s.
(a) Find the magnitude of the acceleration of the block.

(b) Find the coefficient of kinetic friction between block and plane.

(c) Find the friction force acting on the block.

(d) Find the speed of the block after it has slid 1.80 m.