Answer:
the value of force, F=4.0N
Explanation:
Firstly, recall velocity-time equation
- v=u+at
- (4)=(2)+a(5)
- a=0.4m/s²
Secondly, recall the Newton's 2nd Law
- <em>F</em><em>=</em><em>ma</em>
- <em>F</em><em>=</em><em>(</em><em>1</em><em>0</em><em>)</em><em>(</em><em>0</em><em>.</em><em>4</em><em>)</em>
- <em>F</em><em>=</em><em>4</em><em>.</em><em>0</em><em>N</em>
Answer:
a. 79.1 N
b. 344 J
c. 344 J
d. 0 J
e. 0 J
Explanation:
a. Since the crate has a constant velocity, its net force must be 0 according to Newton's 1st law. The push force
by the worker must be equal to the friction force
on the crate, which is the product of friction coefficient μ and normal force N:
Let g = 9.81 m/s2

b. The work is done on the crate by this force is the product of its force
and the distance traveled s = 4.35

c. The work is done on the crate by friction force is also the product of friction force and the distance traveled s = 4.35

This work is negative because the friction vector is in the opposite direction with the distance vector
d. As both the normal force and gravity are perpendicular to the distance vector, the work done by those forces is 0. In other words, these forces do not make any work.
e. The total work done on the crate would be sum of the work done by the pushing force and the work done by friction

The force exerted by a magnetic field on a wire carrying current is:

where I is the current, L the length of the wire, B the magnetic field intensity, and

the angle between the wire and the direction of B.
In our problem, the force is F=0.20 N. The current is I=1.40 A, while the length of the wire is L=35.0 cm=0.35 m. The angle between the wire and the magnetic field is

, so we can re-arrange the formula and substitute the numbers to find B:
Answer:
a=F/m
a=12N/3kg (here newton can be written as kgm/s^2 so kg will be cancelled)
a=4m/s^2
Explanation: