Answer:(a)891.64 N
(b)0.7
Explanation:
Mass of crate 
Crate slows down in 
initial speed 
inclination 
From Work-Energy Principle
Work done by all the Forces is equal to change in Kinetic Energy




change in kinetic energy

(b)Coefficient of sliding friction



and 


Magnet moving left to right
Answer:
980 J
Explanation:
The change in box's energy is equal to its change in gravitational potential energy:

where
m = 50 kg is the mass of the box
g = 9.8 m/s^2 is the acceleration due to gravity
is the change in height of the box
Substituting numbers, we find

Answer:
80% (Eighty percent)
Explanation:
The material has a refractive index (n) of 1.25
Speed of light in a vacuum (c) is 2.99792458 x 10⁸ m/s
We can find the speed of light in the material (v) using the relationship
n = c/v, similarly
v = c/n
therefore v = 2.99792458 x 10⁸ m/s ÷ (1.25) = 239 833 966 m/s
v = 239 833 966 m/s
Therefore the percentage of the speed of light in a vacuum that is the speed of light in the material can be calculated as
(v/c) × 100 = (1/n) × 100 = (1/1.25) × 100 = 0.8 × 100 = 80%
Therefore speed of light in the material (v) is eighty percent of the speed of light in the vacuum (c)
Answer:
The magnitude of the resultant acceleration is 2.2 
Explanation:
Mass (m) of the sailboat = 2000 kg
Force acting on the sailboat due to ocean tide is
= 3000N
Eastwards means takes place along the positive x direction
Then
= 3000N and
= 0
Wind Force acting on the Sailboat is
= 6000N directed towards the northwest that means at an angle 45 degree above the negative x axis
Then
= -(6000N) cos 45 degree = -4242.6 N
= (6000N) cos 45 degree = 4242.6 N
Hence , the net force acting on the sailboat in x direction is

= - 3000 N + 4242.6 N
= - 3000 N +4242.6 N
= 1242.6N
Net Force acting on the sailboat in y direction is

= 0+ 4242.6N
= 4242.6N
The magnitude of the resultant force =
Using pythagorean theorm of 1243 N and 4243 N



4420.8 N
F = ma


=2.2 