Answer:
maximum force (in N) can you exert horizontally on the crate without moving it = 564.075 N
Explanation:
Given data:
mass m= 115 kg
coefficient of friction μ =0.5
according to newton law of motion the net force acted on body is given by

here the body is in rest ,

N= it is the normal reaction force
N= mg = 115×9.81
therefore,

Answer:
Explanation:
Given
mass of car 
Initial velocity of car
towards east
Time taken to stop 
Force exerted 
change in momentum is given by impulse imparted to the car



negative Sign indicates that impulse is imparted opposite to the direction of motion
magnitude of momentum 
Answer:
B. X-rays
Explanation:
From the given choices, x-rays will have the highest energy of the given waves.
The energy of electromagnetic waves is highly dependent on their frequency and wavelength.
Electromagnetic waves with a high frequency and small wavelength will have higher energy compared to those with low frequency and high wavelength.
X-rays are one the most energetic waves on the periodic table. They have a very high frequency and low wavelength.
Answer:
c) 
Explanation:
Coulomb's law says that the force exerted between two charges is inversely proportional to the square of distance between them, and is given by the expression:

where k is a proportionality constant with the value 
In this case
, so we have:

Solving the equation for q, we have:



Replacing the given values:

