Mechanics | Relativity Answers

why we take sin in cross product & cos in dot product?

a ball slowly rolls off a 1 meter high table and falls straight down. how long does it take for the ball to hit the floor and how fast will it be going just before it hits the floor? the accelerations of the ball due to gravity is 9.81 m/sec^2

A UFO is currently 500m away from the surface of the earth. At this moment it has a velocity of 50 m/s away from the earth and a constant acceleration of 100 m/s away from the earth. What is the velocity of the UFO in 10 seconds? How far is the UFO from the surface of the earth in 10 seconds?

tony stewart has a fast reaction time of 0.125s. While he is racing at a constant velocity of 185 mph he sees a crash in front of him. It takes him 0.125 s to step on the brakes after seeing the accident. Once he steps on the brakes, the car undergoes a constant acceleration of -8.45 m/s2 (1 mile= 1609m) How long does it take him to come to a complete stop? How far does he go before coming to a stop?

You are driving 57 km/h towards an intersection when the light turns yellow. At that moment, you are 34. m away from the stop bar. Given the typical human reaction time of 0.3 seconds, brakes that provide ab acceleration of 5.37m/s^2, and only 2.9 seconds before the light turns red answer the following question: To avoid having your car enter the intersection after the light turns red should you attempt to stop or should you continue through the intersection without braking? Which of these strategist will work for you?

Rain falls from a cloud 1.73 km above you. Ignoring air resitance, what is the speed of a raindrop when it his the ground in meters per second?

A father and his son are supposed to carry a load of 500 N. They decided to use a uniform pole that is 4.0 m long and weighs 60 N. The father and his son support the pole at the ends. Where should the load be placed so that the father supports three times as much as his son?

a plate thrown straight up has a zero velocity at its highest point. is the ball in equilibrium at this point?

a ball which is thrown Vertically up words reaches the roof of a house 100 m high.at the moment this ball is thrown vertically up ward ,another ball is dropped from rest vertically downwards from the roof of the house.at which time, height the ball will pass each other.

A car slows down from 25 m/s to rest in a distance of 93 m. What was its acceleration, assumed constant?