Mechanics | Relativity Answers

"the law of conservation of linear momentum,as applied to a single particle,is equivalent to newton's first law of motion"Justify.

A playground is on the flat roof of a city school, 6.1 m above the street below (see figure). The vertical wall of the building is h = 7.50 m high, forming a 1.4-m-high railing around the playground. A ball has fallen to the street below, and a passerby returns it by launching it at an angle of θ = 53.0°; above the horizontal at a point d = 24.0 m from the base of the building wall. The ball takes 2.20 s to reach a point vertically above the wall.

(a) Find the speed at which the ball was launched. (Give your answer to two decimal places to reduce rounding errors in later parts.)

A ball is thrown vertically upwards and travels freely under gravity. Three seconds later it has a speed of 4.4 ms-1 but its direction has changed. Find the initial velocity of the particle, can I see working as well?

In an automobile race the cars are started with a starter car traveling at 31.5 m/sec. If

the lead car has an average acceleration of 4.3 m/sec2 during the first 3 seconds, how
fast was it traveling at the end of 3 seconds and how far did it go?

I wasn't sure what category to ask this in, but this one seemed like the best bet. My question involves force and surface area.

Let's say there are two objects, Object A and Object B:
-Object A weighs a little less than Object B
-Object A has far more surface area than Object B
-Both Object A and Object B are being supported by identical structures

Which will have more force on the structure? How do I calculate the force (or would it be pressure?) that each object has on the structure?

A block of mass m = 2.00 kg is released from rest at h = 0.800 m from the surface of a table, at the top of a θ = 30.0° incline as shown below. The frictionless incline is fixed on a table of height H = 2.00 m.
(a) Determine the acceleration of the block as it slides down the incline.
(b) What is the velocity of the block as it leaves the incline?
(c) How far from the table will the block hit the floor?
(d) How much time has elapsed between when the block is released and when it hits the floor?

A bullet is fired from a rifle that is held 1.5m above the ground in a horizontal position. The Initial speed of the bullet is 1210 m/s. find (a) the time it takes for the bullet to strike the ground (b) the horizontal distance traveled by the bullet

hi i have a question for you,
To set a speed record in measured straight line distance d, a race car must be driven first in one direction in time t1 and then in the opposite direction time t2. a) to eliminate the effects of the wind and obtain the ca's speed Vc in a windless situation, should we find the average of d/t1 and d/t2 (method 1) or should we devidee d by the average of t1 and t2. b) what is the fractional difference in the two methods when a steady wind belows along the car's route and the ratio of the wind speed Vw to the car's speed Vc is 0.0180

An object moves with constant acceleration 3.40 m/s2 and over a time interval reaches a final velocity of 11.8 m/s.
(a) If its initial velocity is 5.9 m/s, what is its displacement during the time interval?
m

(b) What is the distance it travels during this interval?
m

(c) If its initial velocity is
−5.9
m/s, what is its displacement during the time interval?
m

(d) What is the total distance it travels during the interval in part (c)?

An archer shoots an arrow into the air with an initial velocity of 75 feet per second. The initial height of the shot is 5 feet. The arrow strikes the ground precisely 200 feet from the archer. At what angle did the archer shoot the arrow?