Answer:
D). energy resulting from the attraction between two masses.
Explanation:
Answer:
Distance moved = 42 meters
Mag and Dir = 10 meters northward
Explanation:
Distance is total distance traveled which = 22+16+4 = 42 meters
Displacement is the amount of distance moved from the start point to the end point straight line so our equation for the magnitude is 22-16+4 = 10 meters. Then the direction is northward from the start point. This answer would also be a vector because it has a magnitude and direction.
1. Answer: A skydiver whose air resistance is equal to that of her weight.
A skydiver free falls under gravity but her rate of fall slows down due to drag -air resistance. when this air resistance becomes equal to her weight, the two get balanced and the body does not accelerate or decelerates.
2. Answer: Gravity
Contact forces are those which act when there is physical contact between two bodies. For example: normal force, tension and spring force.
Non-contact forces act between two bodies even when they are at a distance apart. For example: gravity, electric force, magnetic force etc.
3. Answer: The tendency of an object's motion to remain the same.
Inertia is a property of matter by virtue of which it tends to remain in its state of motion or rest. It does depend on mass of the object, more the mass, more is inertia. For example, cycle can be easily moved but we need real push hard for a car to move.
4. Answer: 254 N
The man pushes the box with 310 N force at an angle of 55 degrees to the horizontal.
we can write this in terms of horizontal (
)and vertical component (
).
Horizontal component: 
Vertical component: 
The vertical component would act towards the floor making the job more difficult to move the job.
The formula we can use here is:
g = G m / r^2
where g is gravity, G is gravitational constant, m is
mass, and r is radius
Since G is constant, therefore we can equate two
situations:
g1 m1 / r1^2 = g2 m2 / r2^2
(10 m/s^2) r1^2 / m1 = g2 * (1/2 r1)^2 / (1/8 m1)
<span>g2 = 5 m/s^2</span>
Answer:
Work Function = 3.53 x 10⁻¹⁹ J = 2.2 eV
Explanation:
The work function of the metal metal can be found as follows:
Energy of Photon = Work Function + K.E
hc/λ = Work Function + K.E
Work Function = hc/λ - K.E
where,
h = Plank's Constant = 6.625 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of photons = 240 nm = 2.4 x 10⁻⁷ m
K.E = Maximum Kinetic Energy = (2.97 eV)(1.6 x 10⁻¹⁹ J/1 eV) = 4.752 x 10⁻¹⁹ J
Therefore,
Work Function = (6.625 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(2.4 x 10⁻⁷ m) - 4.752 x 10⁻¹⁹ J
Work Function = 8.281 x 10⁻¹⁹ J - 4.752 x 10⁻¹⁹ J
<u>Work Function = 3.53 x 10⁻¹⁹ J = 2.2 eV</u>