Mechanics | Relativity Answers

A fly ball is hit with an angle of 80 degrees with a initial speed of 40.0 m/s. How long does the fielder have to get underneath the ball? And what is the maximum height attained by the ball?

A building superintendent twirls a set of keys in a circle at the end of a cord. If the keys have a centripetal acceleration of 127 m/s^12 and the cord has a length of 0.22 m, what is the tangential speed of the keys?

A car is rounding an unbanked circular turn with a speed of v = 35 m/s. The radius of the turn is r = 1500 m. What is the magnitude ac of the car’s centripetal acceleration?




0.82 m/s2


1.8 × 106 m/s2


0.023 m/s2


5.4 × 10-4 m/s

A jogger runs along a straight and level road for a distance of 8.0 km and then runs back to her starting point. The time for this roundtrip is 2.0 h. Which one of the following is true?




Her average speed is 8.0 km/h, and her average velocity is 8.0 km/h.


Her average speed is 8.0 km/h, but there is not enough information to determine her average velocity.


Her average speed is 8.0 km/h, and her average velocity is 0 km/h

a stone is tied to a weightless string and revolved in a vertical circle of radius 5m. (i) what should be the minimum speed of the stone at the highest point of the circle so that the string does not slack? (II) What should be the speed of the stone at the lowest point in this situation?

Every Morning a student jogs around 200m track four times in 30mins. What is the students:
Average speed and Average velocity? show me a solution.

The angular velocity of circular disc of radius 2cm is 20 rad/s calculate the linear velocity of disc ??????????

The position x of particle with respect to time t along x-axis is given by X=9 t square - t cube ,where x is in meters and t in seconds. what will be the position of this particle when it achieves maximum speed along the +x direction ?

Motion of a particle is given by equation s= (3 t cube+ 7 t square +14 t + 8 )m the value of acceleration of the particle at t=1s is ???????????????????????????

The position x of a particle varies with time ,(t) as x=a t square -b t cube .the acceleration will zero at time t equals to ????????????????????