Mechanics | Relativity Answers

The speed limit in a school zone is 40 km/hr. A driver traveling at this speed sees a child run onto the road 13 m ahead of his car. He applies the brakes, and the car decelerates at a uniform rate of 8 m/s². If the driver’s reaction time is 0.25 s, will the car stop before hitting the car?

The speed limit in a school zone is 40 km/hr. A driver traveling at this speed sees a child run onto the road 13 m ahead of his car. He applies the brakes, and the car decelerates at a uniform rate of 8 m/s². If the driver’s reaction time is 0.25 s, will the car stop before hitting the car?

In order to get his car out of the mud, a man ties one end of a rope to the front bumper and

the other end to a tree 15 m away, as shown below. He then pulls on the center of the rope

with a force of 400 N, which causes its center to be displaced 0.30 m, as shown. What is the

force of the rope on the car?

A 90000 lbs truck is braked to a stop in 95 ft. from an initial speed of 95 ft/s . How

much force was required ?

If you have a mass of 55 kg and you are standing 3 meters away from your car, which has a mass of 1234 kg, how strong is the force of gravity between you and the car?

With its engine cut off, a small airplane glides downward at an angle of 15° below the 

horizontal at a speed of 240 km/h. (a) What are the horizontal and the vertical 

components of its velocity? (b) If the airplane is initially at a height of 2000 m above the 

ground, how long does it take to crash into the ground?  

Note: For (a), you may use m/s or km/h as long as you indicate, and you are consistent 

with the unit that you use. For (b) you may use seconds(s) or minute(m), just indicate the 

unit used.

A ball of mass 0.25kg loses one third of it's velocity on collision with an identical ball 9/2 at rest after collision q moves off with a speed of 2m/s in the original direction of p. Calculate the original velocity of p.

Show that the period of oscillation on a main helical spring is given by T=2π√{k/m}

if the velocity of a particle is defined by v = (2t + 1)i +3j fps, and is position vector at t = 1 sec is t = 4i+ 3j ft, determine the path of the particle in terms of its x and y coordinates.

Give a reason why it is much more useful to plot a graph of acceleration against the inverse of mass, than it is to plot a graph of acceleration against mass.