Physics Magnetism,Magnetic Effects Of Current Level: Misc Level
In a television set,electrons are accelerated from rest through a potential difference of 22 kV. The electrons then pass through a 0.30 T magnetic field that deflects them to the appropriate spot on the screen. Find the magnitude of the maximum magnetic force than an electron can experience....N
Physics Magnetism,Magnetic Effects Of Current Level: Misc Level
At a certain location, the horizontal component of the earth,s magnetic field is 2.60x 10-5 T, due north.A proton moves eastward with just the right speed, so the magnetic force on it balance its weight. Find the speed of the proton. m/s
Physics Gravitation Level: Misc Level
A system consists of three particles, each of mass 4.00 g, located at the corners of an equilateral triangle with sides of 31.0 cm
(a) Calculate the potential energy of the system. (Assume that U=0 as r---00.)J
(b) If the particles are released simultaneously, where will they collide?
1. at an edge
2. at the center
3. will never collide
4. at a corner
Physics Gravitation Level: Misc Level
A synchronous satellite, which always remains above the same point on a planet,s equator, is put in orbit around Saturn so that scientists can study a surface feature. Saturn rotates once every 10.5 h. Use the data of Table 13.2 to find the alittude of the satellite.
Physics Gravitation Level: Misc Level
Three uniform spheres of mass m1=1.50 kg, 4.00 kg, and m2=6.50 kg are placed at the corners of a right triangle as in Figure P 13.5. Calculate the resultant gravitational force on the 4.00 kg object, assuming the spheres are isolated from the rest of the Universe. iN+ jN
Physics Force & Laws Of Motion Level: Misc Level
Block A, with a mass of 10 kg, rests on a 30% incline ,The coefficient of kinetic friction is 0.20. The attached string is parallel to the incline and passes over a massless, frictionless pulley at the top. Block B, with a mass of 3.0 kg, is attached to the dangling end of the string . Find the acceleration of B (magnitude and direction);
Physics Force & Laws Of Motion Level: Misc Level
Why do raindrops fall with constant speed during the later stages of their descent?
a.The gravitational force is the same for all drops
b. Air resistance just balances the force of gravity
c. The drops all fall from the same height
d. The force of gravity is negligible for objects as samall as raindrops
e. Gravity cannot increase the speed
of a falling object to none these ft/s
Physics Force & Laws Of Motion Level: Misc Level
A 1000-kg airplane moves in straight flight at constant speed. The force of air friction is 1800 N. The net force on the plane is;
a. zero
b.11800 N
c. 1800 N
d. 9800 N
e. none of these
Physics Force & Laws Of Motion Level: Misc Level
The system shown remains at rest. Find the force of friction on the upper block;
Physics Force & Laws Of Motion Level: Misc Level
A block is first placed on its long side and then on its short side on the same inclined plane. The block slides down the plane on its short side but remains at rest on its long side.A possible explanation is;
a. the short side is smoother
b. the frictional force is less because the contact area is less
c.case
d. the normal force is less in the second case
e. the force of gravity is more nearly down the plane in the second case
Physics Force & Laws Of Motion Level: Misc Level
A 400-N block is dragged along a rough (uk=0.4) horizontal surface by an applied force c as shown. The block moves at constant velocity. Find the magnitude of F;
Physics Force & Laws Of Motion Level: Misc Level
A horizontal shove of at least 200-N is required to start moving a 800-N crate initially at rest on a horizontal floor. Find the coefficient of static friction is;
Physics Force & Laws Of Motion Level: Misc Level
A brick slides on a horizontal surface. Which of the following will increase the friction force on it?
a. Putting a second brick on top
b. Decreasing the surface area of contact
c. Increasing the surface area of contact
d. Decreasing the mass of the brick
e. None of the above
Physics Force & Laws Of Motion Level: Misc Level
Two blocks with masses m and M are pushed along a horizontal frictionless surface by a horizontal applied force c as shown. The magnitude of the force that either of these blocks exerts on the other is;
a. mF/ m+M)
b.mF/M
c. mF (M-m)
d. MF(M+m)
e. MF/m
Physics Force & Laws Of Motion Level: Misc Level
Three blocks (A,B, C),each having mass M, are connected by strings as shown. Block C is pulled to the right by a c that causes the entire system to accelerate. Neglecting friction, find the net force acting on block B;
