Answer:
2 min 40 s.
Explanation:
Distance = 800 ft
Speed (walking speed) = 300 ft/min
Speed = distance/time
Time, t = 800/300
= 8/3
= 2 min 40 s.
Answer:
1. Efficiency
2. Kinetic energy
3. Pulley
4. Screw
5. Wedge
Explanation:
1. Efficiency: the ratio of work output to work input or the ratio of actual mechanical advantage (AMA) to ideal mechanical advantage (IMA).
Mathematically, the efficiency of a machine is given by the formula;
2. Kinetic energy: the energy of a moving object. Kinetic energy (KE) is an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;

Where;
K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
3. Pulley: a grooved wheel over which a rope can move. It is made up of a wheel and rope which allows force to be multiplied such as in a drawing well.
4. Screw: a double-sided inclined plane. It is held in position and then used to tighten two or more objects together.
5. Wedge: an inclined plane wrapped around a cylinder. It can be used to split objects into halves.
Answer:
shrinks with all the fringes getting narrower
Explanation:
As the light passes through the slit, the diffraction pattern shrinks, as the waves have more opening to penetrate, and the fringes becomes more narrow as a result of that, The opposite happens as the conditions are reversed.
B. An increase in your mass
Because acceleration is inversely proportional to the mass of the object.

Answer:
d = 8.4 cm
Explanation:
In order to calculate the amplitude of oscillation of the top of the building, you use the following formula for the max acceleration of as simple harmonic motion:
(1)
A: amplitude of the oscillation
w: angular speed of the oscillation = 2
f
f: frequency = 0.17Hz
The maximum acceleration of the top of the building is a 2.0% of the free-fall acceleration. Then, you have:

Then, you solve for A in the equation (1) and replace the values of the parameters:

The total distance, side to side, of the oscilation of the top of the building is twice the amplitude A. Then you obtain:
d = 2A = 2(4.2cm) = 8.4cm