Mechanics | Relativity Answers

A boat is moving at 30 kph in crossing a river in which the current is flowing at 12 kph.In what direction should the boat head if it is to reach a point on the other side of the river directly opposite its starting point.check your answer with a graphical solution.

An 800 kg car moving at 30 m/s brakes and skids to a stop over surface with coefficient of friction 0.60 make diagram and find force of friction and distance to stop

At t = 0, one toy car is set rolling on a straight track with initial position 14.5 cm, initial velocity -3.1 cm/s, and constant acceleration 2.60 cm/s2. At the same moment, another toy car is set rolling on an adjacent track with initial position 12.0 cm, initial velocity 5.70 cm/s, and constant zero acceleration.

(c) At what time(s), if any, do the cars pass each other? (If there is only one time, enter NA in the second blank. If there are two times, enter the smaller time first. If they never pass, enter NA in both blanks.)

A girl delivering newspapers travels 5 blocks
west, 7 blocks north, then 8 blocks east.
What is the magnitude of her resultant dis-
placement?

Statement-1 : Velocity and acceleration of a particle are given as :
= î – ĵ and = 2î + 2ĵ
This is a two dimensional motion with constant acceleration.
Statement-2 : Velocity and acceleration are two constant vectors.

A spring of stiffness 2o KN/m supports a mass of 4 Kg. the mass is pulled down 8 mm and released to produce linear oscillations. calculate the frequency and periodic time. sketch the graphs of displacement, velocity and acceleration. calculate the displacement, velocity and acceleration 0.05 s after released.

note X= A sin(w t + phase angle)

X : displacement
A : amplitude
w : omega
t : periodic time
ceta : phase angle

Two 10kg masses are suspended at the two ends of a rope , which passes over a light frictionless pulley . The pulley attached to a chain , which goes to the ceiling . What is the tension in the rope and chain ?

What will be the direction of frictional force , separately in the cases of Pure rolling, forward slipping and backward slipping? Please can you explain this with some diagrams ?

A car accelerates from rest and reaches a speed of 25m\s in 7.6s. if the diameter of a tire is 0.680 m , find the revolutions the tire makes during the motion?

To qualify for the finals in a racing event, a race car must achieve an average speed of 245 km/h on a track with a total length of 1,700 m. If a particular car covers the first half of the track at an average speed of 222 km/h, what minimum average speed must it have in the second half of the event in order to qualify?