|
A ball is thrown upward from the ground. You observe the ball through a window on its way up, and notice it was visible for 2 seconds while it travels from the bottom of the window to the top, which is a length of 43.42 metres. a) How much time does it take for the ball to be seen again (in seconds)? b) How far above top of window will the ball reach (in metres)? |
In: Physics
A sheet of charge with ρS = 8 nC/m2
is in the plane x = 5 in free space and a line
charge ρL = 15 nC/m is located at x = 2, z = 5.
a. Find E at P(0, 0, 0)
b. E at (4, 5, 6)
c. What is the force per unit length on the line charge?
In: Physics
In: Physics
A soccer player takes a corner kick, lofting a stationary ball 36.0° above the horizon at 16.0 m/s. If the soccer ball has a mass of 0.425 kg and the player's foot is in contact with it for 4.80 ✕ 10−2 s, find the x- and y-components of the soccer ball's change in momentum and the magnitude of the average force exerted by the player's foot on the ball.
(a)
the x- and y-components of the soccer ball's change in momentum (in kg · m/s)
Δpx
= kg · m/s
Δpy
= kg · m/s
(b)
the magnitude of the average force exerted by the player's foot on the ball (in N)
N
In: Physics
You have been hired as a technical consultant for an early-morning cartoon series for children to amke sure that the science is correct. In the script, a wagon containing two boxes of gold (total mass of 150kg) has been cut loose from the horses by an outlaw. The wagon starts from rest 50 meters up a hill with a 6 degree slope. The outlaw plans to have the wagon roll down the hill and across the level fround and then crash into a canyon where his confederates wait. But in a tree 40 meters from the edge of the canyon wait the lone ranger (mass 80kg) and Tonto (mass 70kg). They drop vertically into the wagon as it passes beneath them. The script states that it takes the lone ranger and tonto 5 seconds to grab the gold and jump out of the wagon, but is this correct? You assume that the wagon rolls with negligeble friciton.
In: Physics
A block with a mass of m = 33 kg rests on a frictionless surface and is subject to two forces acting on it. The first force is directed in the negative x-direction with a magnitude of F1 = 11.5 N. The second has a magnitude of F2 = 23 N and acts on the body at an angle θ = 22° measured from horizontal, as shown. write an expression for the component of net force, Fnet,x, in the x direction, in terms of the variables giving in the problem statement. write an expression for the magnitube of the normal force, Fn, acting on the block, F2 and the other variables of the problem. Assume that the surface it rests on it rigid. Find the block's acceleration in the x-direction, ax, in meters per second squared
In: Physics
How is the direction of torque perpendicular to the plane of rotation (according to the cross product of F and r)? It seems very counterintuitive and doesn't seem to make sense.
In: Physics
Consider the following:
If two equal mass objects had the same change in kinetic energy
during an interval, then they were acted on by the same net force
for that interval.
(a) Is this statement valid? __________
(b) If you contend the statement is valid, how do you know?
(c) If you contend the statement is invalid, what is wrong with
it?
(d) If the statement is invalid, restate it to give a valid
statement.
(e) Is the valid statement (original, or your revision) a
conditional or a bi-conditional? How do you know?
In: Physics
Water molecules have a dipole moment of 6.2 x 10-30 C-m because oxygen is more electronegative than hydrogen. If a water molecule sits at the origin and an electron sits at x= 10 nm, what is the magnitude of the force on the electron in fN? "f" is for femto b. In which direction is the force on the electron at x = 10 nm? c. What is the force on an electron that sits at y = 10 nm in fN? d. In which direction is the force on the electron at y = 10 nm?
In: Physics
In: Physics
A ball is dropped from a building of height 100m. At the same time, another ball is then thrown vertically up from the ground with a velocity V0. They meet each other at the middle. What is the speed V0 of the ball thrown vertically up?
a) 44.3m/s
b)9.8m/s
c) 31.3m/s
d)19.6 m/s
e) 98.0m/s
In: Physics
In: Physics
In: Physics
A charge of 3.06 is held fixed at the origin. A second charge of 3.06 is released from rest at the position (1.11 m, 0.524 m). If the mass of the second charge is 2.73 g, what is its speed when it moves infinitely far from the origin? At what distance from the origin does the 3.06 charge attain half the speed it will have at infinity?
In: Physics
In: Physics