Jogging Jake runs at 4 m/s along a train flatcar that moves at 10 m/s in the opposite direction. Jake's speed relative to the ground is
A) 6 m/s.
B) 10 m/s.
C) 14 m/s.
D) none of the above
Answer: A
You might also like to view...
Two cars collide head-on on a level friction-free road. The collision was completely inelastic and both cars quickly came to rest during the collision. What is true about the velocity of this system's center of mass?
A) It was always zero. B) It was never zero. C) It was not zero, but ended up zero. D) none of the above
The ______________ angle is measured between the horizon and the line of sight to the object
a. declination b. altitude c. inclination d. zenith
A airplane having a metal surface and a wingspan of 25.0 m flies horizontally at 200. m/s where the earth's magnetic field is vertical with magnitude 45.0 ?T
(a) What emf is induced across the wings? (b) What wingspan would the plane need to produce 1.00-V emf across its wings? (c) The plane now reverses direction. Does the polarity of the wingtip emf change? That is, if the left wing was positive before, does it now become negative?
A charge of 25 nC is uniformly distributed along a circular arc (radius = 2.0 m) that is subtended by a 90-degree angle. What is the magnitude of the electric field at the center of the circle along which the arc lies?
a. 81 N/C b. 61 N/C c. 71 N/C d. 51 N/C e. 25 N/C