Answer:
f = 692 N
Explanation:
given data:
f =800N
a =1.2 m s^{2}
m= 90 kg
from newton's second law
net force 
therefore we have from above equation
ma =F - f
putting all value to get force of friction
1.2*90 = 800 - f
f = 692 N
The answer is c because a metallic bond Is 1. formed of the attraction between positively charged metal nuclei
2. and surrounding sea electrons
Answer:
V=15.3 m/s
Explanation:
To solve this problem, we have to use the energy conservation theorem:

the elastic potencial energy is given by:

The work is defined as:

this work is negative because is opposite to the movement.
The gravitational potencial energy at 2.5 m aboves is given by:

the gravitational potential energy at the ground and the kinetic energy at the begining are 0.

Linear momentum has to be conserved. It was zero before the thread eas burned ... when nothing was moving ... so the momentum of the masses moving in opposite directions has to add up to zero. ... Momentum = mass times speed. ... In one direction, you have 5 kg times 1/5 m/s= 1 kg-m/s. ... We need 1 kg-m/s in the other direction. ... 7 kg times speed = 1 kg-m/s. ... Can you finish it from here ?
Answer:
Explanation:
Let the amplitude of individual wave be I and resultant amplitude be 1.703 I . Let the phase difference be Ф in terms of degree
From the formula of resultant vector
(1.703I)² = I² + I² + 2 I² cosФ
2.9 I² = 2I² + 2 I² cosФ
.9I² = 2 I² cosФ
cosФ = .9 / 2
= .45
Ф = 63.25 .